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Hatch-McChesney A, Whitney CC, Richardson M, Barrett A, Karl JP. Independent effects of volume and energy density manipulation on energy intake and appetite in healthy adults: A randomized, controlled, crossover study. Appetite 2024; 200:107537. [PMID: 38825013 DOI: 10.1016/j.appet.2024.107537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 05/29/2024] [Accepted: 05/30/2024] [Indexed: 06/04/2024]
Abstract
Consuming enough energy to meet high energy demands can be challenging for military personnel wherein logistical constraints limit food availability. Increasing dietary energy density (ED) and/or volume density (VD) of rations may be countermeasures, but whether positive linear associations between ED and energy intake (EI) hold at moderate-to-high ED and VD is unclear. This study examined the effects of covertly increasing the ED and VD of moderate ED (≥1.6 kcal/g) foods on appetite and energy intake. Twenty healthy men completed four 2-day treatments in random order by consuming a standardized diet containing three experimental food items (EXP) engineered using leavening, physical compression and fat manipulation to be isovolumetric but lower (L) or higher (H) in ED and VD creating four treatments: LED/LVD, LED/HVD, HED/LVD, HED/HVD. Consumption of EXP was compulsory during two meals and a snack, but remaining intake was self-selected (SSF). Results failed to show any ED-by-VD interactions. During LVD, EI was lower for EXP (-417 kcal [95%CI: 432, -402], p < 0.01) and TOTAL (SSF + EXP) (-276 kcal [95%CI: 470, -83], p = 0.01) compared to HVD, while SSF EI did not differ (140 kcal [-51, 332], p = 0.15). During LED, EI for EXP (-291 kcal [95%CI: 306, -276], p < 0.01) was lower than HED, while SSF EI was higher than HED (203 kcal 95%CI: [12, 394], p = 0.04) and TOTAL EI did not differ (-88 kcal [-282, 105], p = 0.36). Thus, when a small isovolumetric portion of the diet was manipulated, increasing the VD of moderate ED foods failed to elicit compensatory reductions in ad libitum EI while increasing the ED of moderate ED foods did. Findings may support VD manipulation of moderate ED foods as a strategy to promote increased short-term EI in environments wherein logistical burden may limit food volume.
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Affiliation(s)
- Adrienne Hatch-McChesney
- Military Nutrition Division, 10 General Greene Ave, United States Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Claire C Whitney
- Military Nutrition Division, 10 General Greene Ave, United States Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Michelle Richardson
- Combat Feeding Division, 10 General Greene Ave, United States Army Development Command Soldier Center, Natick, MA, USA
| | - Ann Barrett
- Combat Feeding Division, 10 General Greene Ave, United States Army Development Command Soldier Center, Natick, MA, USA
| | - J Philip Karl
- Military Nutrition Division, 10 General Greene Ave, United States Army Research Institute of Environmental Medicine, Natick, MA, USA.
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Coca M, Besançon L, Erblang M, Bourdon S, Gruel A, Lepetit B, Beauchamps V, Tavard B, Oustric P, Finlayson GS, Thivel D, Malgoyre A, Tardo-Dino PE, Bourrilhon C, Charlot K. Twenty four-hour passive heat and cold exposures did not modify energy intake and appetite but strongly modify food reward. Br J Nutr 2024:1-18. [PMID: 38634266 DOI: 10.1017/s0007114524000825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
Effects of acute thermal exposures on appetite appear hypothetical in reason of very heterogeneous methodologies. The aim of this study was therefore to clearly define the effects of passive 24-h cold (16°C) and heat (32°C) exposures on appetitive responses compared with a thermoneutral condition (24°C). Twenty-three healthy, young and active male participants realised three sessions (from 13.00) in a laboratory conceived like an apartment dressed with the same outfit (Clo = 1). Three meals composed of three or four cold or warm dishes were served ad libitum to assess energy intake (EI). Leeds Food Preference Questionnaires were used before each meal to assess food reward. Subjective appetite was regularly assessed, and levels of appetitive hormones (acylated ghrelin, glucagon-like peptite-1, leptin and peptide YY) were assessed before and after the last meal (lunch). Contrary to the literature, total EI was not modified by cold or heat exposure (P = 0·120). Accordingly, hunger scores (P = 0·554) were not altered. Levels of acylated ghrelin and leptin were marginally higher during the 16 (P = 0·032) and 32°C (P < 0·023) sessions, respectively. Interestingly, implicit wanting for cold and low-fat foods at 32°C and for warm and high-fat foods at 16°C were increased during the whole exposure (P < 0·024). Moreover, cold entrées were more consumed at 32°C (P < 0·062) and warm main dishes more consumed at 16°C (P < 0·025). Thus, passive cold and hot exposures had limited effects on appetite, and it seems that offering some choice based on food temperature may help individuals to express their specific food preferences and maintain EI.
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Affiliation(s)
- Maxime Coca
- Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 Place Général Valérie André, 91223 Brétigny Cedex, France
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
| | - Louis Besançon
- Hôpital d'instruction des armées Percy, 92140 Clamart, France
| | - Mégane Erblang
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
| | - Stéphanie Bourdon
- Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 Place Général Valérie André, 91223 Brétigny Cedex, France
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
| | - Arnaud Gruel
- Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 Place Général Valérie André, 91223 Brétigny Cedex, France
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
| | - Benoît Lepetit
- Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 Place Général Valérie André, 91223 Brétigny Cedex, France
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
| | - Vincent Beauchamps
- Unité Fatigue et Vigilance, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 Place Général Valérie André, 91223 Brétigny Cedex, France
- EA 7330 VIFASOM, Université de Paris, 75004 Paris, France
| | - Blandine Tavard
- Centre Interarmées du Soutien « Equipements Commissariats », Service du commissariat des armées, 78120 Rambouillet, France
| | - Pauline Oustric
- Inserm, U1296 Unit, "Radiation: Defense, Health and Environment", Centre Léon Bérard, 28 rue Laënnec, 69008 Lyon, France
| | - Graham S Finlayson
- Appetite Control Energy Balance Research Group, School of Psychology, Faculty of Medicine and Health, University of Leeds, LeedsLS2 9JT, UK
| | - David Thivel
- Laboratoire des adaptations Métaboliques à l'Exercice en conditions Physiologiques et Pathologiques (EA 3533), Université Clermont Auvergne, Clermont-Ferrand, France
| | - Alexandra Malgoyre
- Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 Place Général Valérie André, 91223 Brétigny Cedex, France
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
| | - Pierre-Emmanuel Tardo-Dino
- Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 Place Général Valérie André, 91223 Brétigny Cedex, France
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
| | - Cyprien Bourrilhon
- Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 Place Général Valérie André, 91223 Brétigny Cedex, France
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
| | - Keyne Charlot
- Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 Place Général Valérie André, 91223 Brétigny Cedex, France
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
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Vikmoen O, Teien HK, Tansø R, Aandstad A, Lander E, Cumming KT, Ellefsen S, Helkala K, Raastad T. Effects of a 10-d Military Field Exercise on Body Composition, Physical Performance, and Muscle Cells in Men and Women. Med Sci Sports Exerc 2024; 56:682-696. [PMID: 37962228 DOI: 10.1249/mss.0000000000003340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
PURPOSE This study aimed to investigate the effects of a demanding military field exercise on physical performance, body composition, and muscle cellular outcomes in men and women. METHODS Ten men (20.5 ± 0.5 yr) and 8 women (21.4 ± 1.4 yr) completed a 10-d field exercise consisting of extensive physical activity with food and sleep restriction. Acquisition of body composition, physical performance, blood, and muscle biopsies samples were done before and 1, 7, and 14 d after the exercise. RESULTS There were no sex differences in the response to the exercise. Body mass was decreased with 5.6% ± 1.8% and fat mass with 31% ± 11% during the exercise. Both were still reduced after 14 d (2.5% ± 2.3%, P < 0.001, and 12.5% ± 7.7%, P < 0.001, respectively). Isometric leg strength did not change. Peak leg extension torque at 240°·s -1 and counter movement jump height were reduced with 4.6% ± 4.8% ( P = 0.012) and 6.7% ± 6.2% ( P < 0.001), respectively, and was still reduced after 14 d (4.3% ± 4.2%, P = 0.002, and 4.1% ± 4.7%, P = 0.030). No changes occurred in fiber CSA, fiber types, proteins involved in calcium handling, or HSP70. During the exercise, αB-crystallin levels decreased by 14% ± 19% ( P = 0.024) in the cytosolic fraction and staining intensity on muscle sections tended to increase (17% ± 25%, P = 0.076). MuRF1 levels in the cytosolic fraction tended to decrease (19% ± 35%) and increased with 85% ± 105% ( P = 0.003) in the cytoskeletal fraction 1 wk after the exercise. CONCLUSIONS The field exercise resulted in reduced body mass and physical performance in both sexes. The ability to produce force at high contraction velocities and explosive strength was more affected than isometric strength, but this was not related to any changes in fiber type composition, fiber area, Ca 2+ handling, or fiber type-specific muscle damage.
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Affiliation(s)
| | - Hilde Kristin Teien
- Norwegian Defence Research Establishment, Comprehensive Defence Division, Kjeller, NORWAY
| | - Rita Tansø
- Norwegian Defence Research Establishment, Comprehensive Defence Division, Kjeller, NORWAY
| | - Anders Aandstad
- Norwegian Defence University College, Norwegian Defence Command and Staff College, Section for Military Leadership and Sport, Oslo, NORWAY
| | - Elise Lander
- Norwegian School of Sport Sciences, Department of Physical Performance, Oslo, NORWAY
| | | | - Stian Ellefsen
- Inland Norway University of Applied Sciences, Faculty for Health and Social Sciences, Lillehammer, NORWAY
| | - Kirsi Helkala
- The Norwegian Defense University College, Norwegian Defence Cyber Academy, Lillehammer, NORWAY
| | - Truls Raastad
- Norwegian School of Sport Sciences, Department of Physical Performance, Oslo, NORWAY
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Pittia P, Blanc S, Heer M. Unraveling the intricate connection between dietary factors and the success in long-term space missions. NPJ Microgravity 2023; 9:89. [PMID: 38092789 PMCID: PMC10719368 DOI: 10.1038/s41526-023-00331-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 10/18/2023] [Indexed: 12/17/2023] Open
Abstract
In recent decades of spaceflight, inadequate caloric intake has posed significant nutritional challenges, contributing to muscle degradation, weakened immune and cardiovascular systems during and after space missions. This challenge becomes more acute on longer exploration missions, where transporting all food for the entire mission becomes a logistical challenge. This places immense pressure on the food system, requiring energy-dense, varied, stable, and palatable food options. Prolonged storage can lead to nutrient degradation, reducing their bioavailability and bioaccessibility to astronauts. Research is essential not only to improve the quality and stability of space food but also to enhance nutrient bioavailability, thereby reducing weight and volume of food. Muscle and bone loss represent major risks during extended spaceflight, prompting extensive efforts to find exercise countermeasures. However, increased exercise requires additional energy intake, and finding the optimal balance between energy needs and the preservation of muscle and bone mass is challenging. Currently, there is no reliable way to measure total energy expenditure and activity-related energy expenditures in real-time. Systematic research is necessary to develop onboard technology for accurate energy expenditure and body composition monitoring. This research should aim to establish an optimal exercise regimen that balances energy requirements while maintaining astronaut strength and minimizing food transport. In summary, this overview outlines key actions needed for future exploration missions to maintain body mass and physical strength of space travellers. It addresses the requirements for food processing and preservation, considerations for space food formulation and production, and the essential measures to be implemented.
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Affiliation(s)
| | | | - Martina Heer
- IU International University of Applied Sciences, Erfurt, Germany.
- University of Bonn, Institute of Nutritional and Food Sciences, Bonn, Germany.
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5
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Margolis LM, Pasiakos SM. Performance nutrition for cold-weather military operations. Int J Circumpolar Health 2023; 82:2192392. [PMID: 36934427 PMCID: PMC10026745 DOI: 10.1080/22423982.2023.2192392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/20/2023] Open
Abstract
.High daily energy expenditure without compensatory increases in energy intake results in severe energy deficits during cold-weather military operations. The severity of energy deficits has been proportionally linked to declines in body mass, negative protein balance, suppression of androgen hormones, increases in systemic inflammation and degraded physical performance. Food availability does not appear to be the predominant factor causing energy deficits; providing additional rations or supplement snack bars does not reduce the severity of the energy deficits. Nutrition interventions that allow greater energy intake could be effective for reducing energy deficits during cold-weather military operations. One potential intervention is to increase energy density (i.e. energy per unit mass of food) by increasing dietary fat. Our laboratory recently reported that self-selected higher energy intakes and reductions in energy deficits were primarily driven by fat intake (r = 0.891, r2 = 0.475), which, of the three macronutrients. Further, soldiers who ate more fat lost less body mass, had lower inflammation, and maintained net protein balance compared to those who ate less fat. These data suggest that consuming high-fat energy-dense foods may be a viable nutritional intervention that mitigates the negative physiological effects of energy deficit and sustains physical performance during cold-weather military operations.
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Affiliation(s)
- Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Stefan M Pasiakos
- Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
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Helén J, Kyröläinen H, Ojanen T, Pihlainen K, Santtila M, Heikkinen R, Vaara JP. High-Intensity Functional Training Induces Superior Training Adaptations Compared With Traditional Military Physical Training. J Strength Cond Res 2023; 37:2477-2483. [PMID: 37387578 PMCID: PMC10671205 DOI: 10.1519/jsc.0000000000004559] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/01/2023]
Abstract
ABSTRACT Helén, J, Kyröläinen, H, Ojanen, T, Pihlainen, K, Santtila, M, Heikkinen, R, and Vaara, JP. High-intensity functional training induces superior training adaptations compared with traditional military physical training. J Strength Cond Res 37(12): 2477-2483, 2023-This study examined the effectiveness of concurrent strength and endurance training with an emphasis on high-intensity functional training (HIFT) during military service. Voluntary male conscripts (aged 18-28 years) were placed in either an experimental (EXP: n = 50-66) or a control (CON: n = 50-67) group. The training for the EXP group included HIFT using body mass, sandbags, and kettlebells. The CON group trained according to the current practice. Physical performance and body composition were assessed at baseline (PRE), at week 10 (MID), and after (POST) the 19-week training period. Significance was set at p < 0.05. The total distance covered in a 12-minute running test increased in both groups, but the change in EXP was superior to the change in CON (11.6%, ES: 0.79 vs. 5.7%, ES: 0.33; p = 0.027). Maximal strength and power characteristics increased in EXP (3.1-5.0%), whereas no improvements were observed in CON. Conscripts with the highest initial fitness showed no improvements in physical performance in either group. Body mass and waist circumference decreased in EXP, whereas CON showed an increase in muscle mass. These findings suggest that HIFT is an effective and time-efficient approach to improve soldiers' aerobic fitness during military service. For the optimal development of strength, the training equipment used may not have provided sufficient and progressive loading to yield considerable strength adaptations. More focus should be placed on sufficient intensity and volume in both strength and endurance training, especially for the most fit soldiers.
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Affiliation(s)
- Joonas Helén
- Department of Leadership and Military Pedagogy, National Defence University, Helsinki, Finland;
| | - Heikki Kyröläinen
- Department of Leadership and Military Pedagogy, National Defence University, Helsinki, Finland;
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylän yliopisto, Finland;
| | - Tommi Ojanen
- Human Performance Division, Finnish Defence Research Agency, Järvenpää, Finland;
| | - Kai Pihlainen
- Training Division, Defence Command, Finnish Defence Forces, Helsinki, Finland; and
| | - Matti Santtila
- Department of Leadership and Military Pedagogy, National Defence University, Helsinki, Finland;
| | - Risto Heikkinen
- Statistical Analysis Services, Analyysitoimisto Statisti Oy, Jyväskylä, Finland
| | - Jani P. Vaara
- Department of Leadership and Military Pedagogy, National Defence University, Helsinki, Finland;
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7
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Messonnier LA. Physical Exercise or Activity and Energy Balance or Metabolism in the Context of Health and Diseases. Nutrients 2023; 15:4909. [PMID: 38068767 PMCID: PMC10708250 DOI: 10.3390/nu15234909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 11/17/2023] [Indexed: 12/18/2023] Open
Abstract
Regular long-lasting physical exercise demands a tremendous amount of metabolic energy [...].
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Affiliation(s)
- Laurent A. Messonnier
- Inter-University Laboratory of Human Movement Sciences, Department of Sport Sciences, University Savoie Mont Blanc, F-73000 Chambéry, France; ; Tel.: +33(0)-4-79-75-81-85
- Institut Universitaire de France (IUF), F-75231 Paris, France
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8
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Garron T, Klein DJ. Male Army ROTC Cadets Fail to Meet Military Dietary Reference Intakes and Exhibit a High Prevalence of Low Energy Availability and Poor Sleep Quality. J Funct Morphol Kinesiol 2023; 8:95. [PMID: 37489308 PMCID: PMC10366743 DOI: 10.3390/jfmk8030095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 06/30/2023] [Accepted: 07/04/2023] [Indexed: 07/26/2023] Open
Abstract
The purpose of this study was to assess the dietary habits, prevalence of low energy availability (EA), and sleep quality in a cohort of male army Reserve Officer Training Corps (ROTC) cadets, and to investigate the relationship between EA and sleep quality as well as EA and various body composition variables that are important for tactical readiness. Thirteen male army ROTC cadets (22.2 ± 4.1 yrs; BMI: 26.1 ± 2.3) had their EA and body composition assessed using diet and exercise records alongside bioelectrical impedance analysis. Cadets also completed a validated sleep questionnaire. Sixty-two percent of participants presented with clinically low EA (<30 kcal/kg fat-free mass [FFM]) and none met the optimum EA threshold (≥45 kcal/kg FFM). Dietary analysis indicated that 15%, 23%, 46%, 23%, and 7% of cadets met the Military Dietary Reference Intakes (MDRI) for calories, carbohydrates, protein, fat, and fiber, respectively. Additionally, 85% of cadets exhibited poor sleep quality. Significant associations between EA and fat mass/percent body fat were shown (p < 0.05). There was, however, no statistically significant correlation between EA and sleep quality. The present study found a high prevalence of low EA and sleep disturbance among male army ROTC cadets and that many were unable to meet the MDRIs for energy and macronutrient intake. Further, low EA was associated with higher percent body fat and fat mass but not sleep quality.
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Affiliation(s)
- Taylor Garron
- Department of Health and Exercise Science, Rowan University, Glassboro, NJ 08028, USA
| | - Dylan J Klein
- Department of Health and Exercise Science, Rowan University, Glassboro, NJ 08028, USA
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9
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Beckner ME, Thompson L, Radcliffe PN, Cherian R, Wilson M, Barringer N, Margolis LM, Karl JP. Sex differences in body composition and serum metabolome responses to sustained, physical training suggest enhanced fat oxidation in women compared with men. Physiol Genomics 2023; 55:235-247. [PMID: 37012051 PMCID: PMC10190831 DOI: 10.1152/physiolgenomics.00180.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/02/2023] [Accepted: 03/28/2023] [Indexed: 04/05/2023] Open
Abstract
Sex differences in energy metabolism during acute, submaximal exercise are well documented. Whether these sex differences influence metabolic and physiological responses to sustained, physically demanding activities is not well characterized. This study aimed to identify sex differences within changes in the serum metabolome in relation to changes in body composition, physical performance, and circulating markers of endocrine and metabolic status during a 17-day military training exercise. Blood was collected, and body composition and lower body power were measured before and after the training on 72 cadets (18 women). Total daily energy expenditure (TDEE) was assessed using doubly labeled water in a subset throughout. TDEE was greater in men (4,085 ± 482 kcal/d) than in women (2,982 ± 472 kcal/d, P < 0.001), but not after adjustment for dry lean mass (DLM). Men tended to lose more DLM than women (mean change [95% CI]: -0.2[-0.3, -0.1] vs. -0.0[-0.0, 0.0] kg, P = 0.063, Cohen's d = 0.50) and have greater reductions in lower body power (-244[-314, -174] vs. -130[-209, -51] W, P = 0.085, d = 0.49). Reductions in DLM and lower body power were correlated (r = 0.325, P = 0.006). Women demonstrated greater fat oxidation than men (Δfat mass/DLM: -0.20[-0.24, -0.17] vs. -0.15[-0.17, -0.13] kg, P = 0.012, d = 0.64). Metabolites within pathways of fatty acid, endocannabinoid, lysophospholipid, phosphatidylcholine, phosphatidylethanolamine, and plasmalogen metabolism increased in women relative to men. Independent of sex, changes in metabolites related to lipid metabolism were inversely associated with changes in body mass and positively associated with changes in endocrine and metabolic status. These data suggest that during sustained military training, women preferentially mobilize fat stores compared with men, which may be beneficial for mitigating loss of lean mass and lower body power.NEW & NOTEWORTHY Women preferentially mobilize fat stores compared with men in response to sustained, physically demanding military training, as evidenced by increased lipid metabolites and enhanced fat oxidation, which may be beneficial for mitigating loss of lean mass and lower body power.
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Affiliation(s)
- Meaghan E Beckner
- U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, United States
| | - Lauren Thompson
- U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
| | - Patrick N Radcliffe
- U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, United States
| | - Rebecca Cherian
- U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
| | - Marques Wilson
- U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
| | - Nicholas Barringer
- Medical Center of Excellence, Joint Base San Antonio-Fort Sam Houston, Texas, United States
| | - Lee M Margolis
- U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
| | - J Philip Karl
- U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
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10
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Nykänen T, Ojanen T, Vaara JP, Pihlainen K, Heikkinen R, Kyröläinen H, Fogelholm M. Energy Balance, Hormonal Status, and Military Performance in Strenuous Winter Training. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:4086. [PMID: 36901097 PMCID: PMC10001933 DOI: 10.3390/ijerph20054086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/16/2023] [Accepted: 02/17/2023] [Indexed: 06/18/2023]
Abstract
Severe energy deficit may impair hormonal regulation and physical performance in military trainings. The aim of this study was to examine the associations between energy intake, expenditure, and balance, hormones and military performance during a winter survival training. Two groups were studied: the FEX group (n = 46) had 8-day garrison and field training, whereas the RECO group (n = 26) had a 36-h recovery period after the 6-day garrison and field training phase. Energy intake was assessed by food diaries, expenditure via heart rate variability, body composition by bioimpedance, and hormones by blood samples. Strength, endurance and shooting tests were done for evaluating military performance. PRE 0 d, MID 6 d, POST 8 d measurements were carried out. Energy balance was negative in PRE and MID (FEX -1070 ± 866, -4323 ± 1515; RECO -1427 ± 1200, -4635 ± 1742 kcal·d-1). In POST, energy balance differed between the groups (FEX -4222 ± 1815; RECO -608 ± 1107 kcal·d-1 (p < 0.001)), as well as leptin, testosterone/cortisol ratio, and endurance performance (p = 0.003, p < 0.001, p = 0.003, respectively). Changes in energy intake and expenditure were partially associated with changes in leptin and the testosterone/cortisol ratio, but not with physical performance variables. The 36-h recovery restored energy balance and hormonal status after strenuous military training, but these outcomes were not associated with strength or shooting performance.
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Affiliation(s)
- Tarja Nykänen
- Army Academy, Finnish Defence Forces, 53600 Lappeenranta, Finland
| | - Tommi Ojanen
- Finnish Defence Research Agency, Finnish Defence Forces, 04310 Tuusula, Finland
| | - Jani P. Vaara
- Department of Leadership and Military Pedagogy, National Defence University, Finnish Defence Forces, 00861 Helsinki, Finland
| | - Kai Pihlainen
- Defence Command, Finnish Defence Forces, 00130 Helsinki, Finland
| | - Risto Heikkinen
- Statistical Analysis Services, Analyysitoimisto Statisti Oy, 40720 Jyväskylä, Finland
| | - Heikki Kyröläinen
- Department of Leadership and Military Pedagogy, National Defence University, Finnish Defence Forces, 00861 Helsinki, Finland
- Faculty of Sport and Health Sciences, University of Jyväskylä, 40114 Jyväskylä, Finland
| | - Mikael Fogelholm
- Department of Food and Nutrition, University of Helsinki, 00014 Helsinki, Finland
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11
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Stein JA, Karl JP, Berryman CE, Harris MN, Rood JC, Pasiakos SM, Lieberman HR. Metabolomics of testosterone enanthate administration during severe-energy deficit. Metabolomics 2022; 18:100. [PMID: 36450940 PMCID: PMC9712311 DOI: 10.1007/s11306-022-01955-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 11/03/2022] [Indexed: 12/02/2022]
Abstract
INTRODUCTION Testosterone administration attenuates reductions in total body mass and lean mass during severe energy deficit (SED). OBJECTIVES This study examined the effects of testosterone administration on the serum metabolome during SED. METHODS In a double-blind, placebo-controlled clinical trial, non-obese men were randomized to receive 200-mg testosterone enanthate/wk (TEST) (n = 24) or placebo (PLA) (n = 26) during a 28-d inpatient, severe exercise- and diet-induced energy deficit. This study consisted of three consecutive phases. Participants were free-living and provided a eucaloric diet for 14-d during Phase 1. During Phase 2, participants were admitted to an inpatient unit, randomized to receive testosterone or placebo, and underwent SED for 28-d. During Phase 3, participants returned to their pre-study diet and physical activity habits. Untargeted metabolite profiling was conducted on serum samples collected during each phase. Body composition was measured using dual-energy X-ray absorptiometry after 11-d of Phase 1 and after 25-d of Phase 2 to determine changes in fat and lean mass. RESULTS TEST had higher (Benjamini-Hochberg adjusted, q < 0.05) androgenic steroid and acylcarnitine, and lower (q < 0.05) amino acid metabolites after SED compared to PLA. Metabolomic differences were reversed by Phase 3. Changes in lean mass were associated (Bonferroni-adjusted, p < 0.05) with changes in androgenic steroid metabolites (r = 0.42-0.70), acylcarnitines (r = 0.37-0.44), and amino acid metabolites (r = - 0.36-- 0.37). Changes in fat mass were associated (p < 0.05) with changes in acylcarnitines (r = - 0.46-- 0.49) and changes in urea cycle metabolites (r = 0.60-0.62). CONCLUSION Testosterone administration altered androgenic steroid, acylcarnitine, and amino acid metabolites, which were associated with changes in body composition during SED.
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Affiliation(s)
- Jesse A. Stein
- Military Nutrition Division, US Army Research Institute of Environmental Medicine (USARIEM), Natick, MA USA
| | - J. Philip Karl
- Military Nutrition Division, US Army Research Institute of Environmental Medicine (USARIEM), Natick, MA USA
| | - Claire E. Berryman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine (USARIEM), Natick, MA USA
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL USA
| | - Melissa N. Harris
- Louisiana State University’s Pennington Biomedical Research Center, Baton Rouge, LA USA
| | - Jennifer C. Rood
- Louisiana State University’s Pennington Biomedical Research Center, Baton Rouge, LA USA
| | - Stefan M. Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine (USARIEM), Natick, MA USA
| | - Harris R. Lieberman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine (USARIEM), Natick, MA USA
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12
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Varanoske AN, Harris MN, Hebert C, Howard EE, Johannsen NM, Heymsfield SB, Greenway FL, Margolis LM, Lieberman HR, Beyl RA, Church DD, Ferrando AA, Pasiakos SM, Rood JC. Testosterone Undecanoate Administration Prevents Declines in Fat-Free Mass but not Physical Performance During Simulated Multi-Stressor Military Operations. J Appl Physiol (1985) 2022; 133:426-442. [PMID: 35796614 PMCID: PMC9359646 DOI: 10.1152/japplphysiol.00190.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
CONTEXT Male military personnel conducting strenuous operations experience reduced testosterone, muscle mass, and performance. Pharmacological restoration of normal testosterone may attenuate performance decrements by mitigating muscle loss. Previously, administering testosterone enanthate (200 mg/week) during energy deficit prompted supraphysiological testosterone concentrations and lean mass gain without preventing isokinetic/isometric deterioration. Whether administering a practical dose of testosterone protects muscle and performance during strenuous operations is undetermined. OBJECTIVE Test the effects of a single dose of testosterone on body composition and military-relevant physical performance during a simulated operation. METHODS After a 7-day baseline phase (P1), 32 males (mean±SD; 77.1±12.3 kg, 26.5±4.4 years) received a single dose of either testosterone undecanoate (750 mg; TEST) or placebo (PLA) before a 20-day simulated military operation (P2), followed by a 23-day recovery (P3). Assessments included body composition and physical performance at the end of each phase and circulating endocrine biomarkers throughout the study. RESULTS Total and free testosterone concentrations in TEST were greater than PLA throughout most of P2 (p<0.05), but returned to P1 values during P3. Fat-free mass (FFM) was maintained from P1 to P2 in TEST (mean±SE; 0.41±0.65 kg, p=0.53), but decreased in PLA (-1.85±0.69 kg, p=0.01) and recovered in P3. Regardless of treatment, total body mass and fat mass decreased from P1 to P2 (p<0.05), but did not fully recover by P3. Physical performance decreased during P2 (p<0.05) and recovered by P3, regardless of treatment. CONCLUSIONS Administering testosterone undecanoate before a simulated military operation protected FFM but did not prevent decrements in physical performance.
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Affiliation(s)
- Alyssa N Varanoske
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Melissa N Harris
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Callie Hebert
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Emily E Howard
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States
| | - Neil M Johannsen
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Steven B Heymsfield
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Frank L Greenway
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Harris R Lieberman
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Robbie A Beyl
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
| | - David D Church
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging and Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Arny A Ferrando
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging and Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Stefan M Pasiakos
- Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Jennifer C Rood
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States
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13
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Gonzalez DE, McAllister MJ, Waldman HS, Ferrando AA, Joyce J, Barringer ND, Dawes JJ, Kieffer AJ, Harvey T, Kerksick CM, Stout JR, Ziegenfuss TN, Zapp A, Tartar JL, Heileson JL, VanDusseldorp TA, Kalman DS, Campbell BI, Antonio J, Kreider RB. International society of sports nutrition position stand: tactical athlete nutrition. J Int Soc Sports Nutr 2022; 19:267-315. [PMID: 35813846 PMCID: PMC9261739 DOI: 10.1080/15502783.2022.2086017] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Affiliation(s)
- Drew E. Gonzalez
- Exercise & Sport Nutrition Laboratory, Human Clinical Research Facility, Department of Health & Kinesiology Texas A&M University, College Station, TX, USA
| | - Matthew J. McAllister
- Texas State University, Metabolic and Applied Physiology Laboratory, Department of Health & Human Performance, San Marcos, TX, USA
| | - Hunter S. Waldman
- University of North Alabama, Department of Kinesiology, Florence, AL, USA
| | - Arny A. Ferrando
- University of Arkansas for Medical Sciences, Department of Geriatrics, Little Rock, AR, USA
| | - Jill Joyce
- Oklahoma State University, Department of Nutritional Sciences, Stillwater, OK, USA
| | - Nicholas D. Barringer
- US. Army-Baylor Master’s Program in Nutrition, Department of Nutrition, San Antonio, TX, USA
| | - J. Jay Dawes
- Oklahoma State University, Department of Kinesiology, Applied Health, and Recreation, Stillwater, OK, USA
| | - Adam J. Kieffer
- Brooke Army Medical Center, Department of Nutritional Medicine, San Antonio, TX, USA
| | - Travis Harvey
- United States Special Operations Command, Preservation of the Force and Family, Tampa, FL, USA
| | - Chad M. Kerksick
- Lindenwood University, Exercise and Performance Nutrition Laboratory, College of Science, Technology, and Health, St. Charles, MO, USA
| | - Jeffrey R. Stout
- University of Central Florida, Institute of Exercise Physiology and Rehabilitation Sciences, School of Kinesiology and Physical Therapy, Orlando, FL, USA
| | | | | | - Jamie L. Tartar
- Nova Southeastern University, Department of Psychology and Neuroscience, Fort Lauderdale, FL, USA
| | - Jeffery L. Heileson
- Baylor University, Department of Health, Human Performance, and Recreation, Waco, TX, USA
| | | | - Douglas S. Kalman
- Dr. Kiran C Patel College of Osteopathic Medicine, Nova Southeastern University, Nutrition Department, Davie, FL, USA
| | - Bill I. Campbell
- University of South Florida, Performance & Physique Enhancement Laboratory, Exercise Science Program, Tampa, FL, USA
| | - Jose Antonio
- Fight Science Laboratory, Nova Southeastern University, Department of Health and Human Performance, Davie, FL, USA
| | - Richard B. Kreider
- Exercise & Sport Nutrition Laboratory, Human Clinical Research Facility, Department of Health & Kinesiology Texas A&M University, College Station, TX, USA
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14
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Charlot K, Millet J, Pasquier F, Oustric P, Finlayson G, Van Beers P, Monin J, Sauvet F, Tardo-Dino PE, Malgoyre A. The impact of 16-h heat exposure on appetite and food reward in adults. Appetite 2022; 177:106144. [PMID: 35753442 DOI: 10.1016/j.appet.2022.106144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 06/20/2022] [Accepted: 06/21/2022] [Indexed: 11/02/2022]
Abstract
Heat exposure is thought to reduce energy intake (EI) but studies are sparse and results not always concordant. The aim of this study was to examine whether a 16-h exposure to 32 °C leads to reduced EI compared to a control session (22 °C) and whether modifications in appetite sensations or food reward are implied. Sixteen healthy, lean, and active participants (9 women and 7 men, 25 ± 5 yo, body mass index: 22.0 ± 2.4 kg.m-2) were passively exposed to two different thermal temperatures from 4:00 pm to 8:00 am under controlled conditions. Hunger and thirst scores were regularly assessed using visual analogue scales. A fixed dinner meal (3670 ± 255 kJ) was consumed at 7:30 pm and an ad libitum breakfast buffet (20 foods/drinks varying in temperature, fat, and carbohydrate content) at 7:30 am. Components of reward (explicit liking [EL] and implicit wanting [EI]) for fat and sweet properties of food were assessed before each meal using the Leeds Food Preference Questionnaire (LFPQ). Ad libitum EI at breakfast did not differ between sessions (2319 ± 1108 vs 2329 ± 1141 kJ, in 22 and 32 °C sessions, respectively; p = 0.955). While thirst scores were higher in the 32 than the 22 °C session (p < 0.001), hunger scores did not differ (p = 0.580). EL and IW for high fat foods relative to low fat foods were decreased in 32 compared to 22 °C before dinner and breakfast (p < 0.001 for all). Although EI and hunger were not affected by a 16-h exposure to heat, modifications in food reward suggested a reduction in the preference of high-fat foods. Future research should investigate whether reduced EI in response to heat exposure is due to spontaneous selection of low-fat foods rather than altered appetite sensations.
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Affiliation(s)
- Keyne Charlot
- Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 place Général Valérie André, 91223, Brétigny Cedex, France; LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025, Evry, France.
| | - Juliette Millet
- Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 place Général Valérie André, 91223, Brétigny Cedex, France; LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025, Evry, France
| | - Florane Pasquier
- French Institute of Sport (INSEP), Laboratory Sport, Expertise and Performance, EA, 7370, Paris, France
| | - Pauline Oustric
- Appetite Control Energy Balance Research Group, School of Psychology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Graham Finlayson
- Appetite Control Energy Balance Research Group, School of Psychology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Pascal Van Beers
- Unité Fatigue et Vigilance, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 place Général Valérie André, 91223, Brétigny Cedex, France; EA 7330 VIFASOM, Université de Paris, 75004, Paris, France
| | - Jonathan Monin
- Centre d'expertise principal du personnel naviguant, Hôpital d'instruction des armées Percy, 94140, Clamart, France
| | - Fabien Sauvet
- Unité Fatigue et Vigilance, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 place Général Valérie André, 91223, Brétigny Cedex, France; EA 7330 VIFASOM, Université de Paris, 75004, Paris, France
| | - Pierre-Emmanuel Tardo-Dino
- Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 place Général Valérie André, 91223, Brétigny Cedex, France; LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025, Evry, France
| | - Alexandra Malgoyre
- Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, 1 place Général Valérie André, 91223, Brétigny Cedex, France; LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025, Evry, France
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15
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Nutrition and Physical Activity During British Army Officer Cadet Training: Part 1-Energy Balance and Energy Availability. Int J Sport Nutr Exerc Metab 2022; 32:195-203. [PMID: 35393372 DOI: 10.1123/ijsnem.2021-0190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 01/07/2022] [Accepted: 02/25/2022] [Indexed: 11/18/2022]
Abstract
Military training is characterized by high daily energy expenditures which are difficult to match with energy intake, potentially resulting in negative energy balance (EB) and low energy availability (EA). The aim of this study was to quantify EB and EA during British Army Officer Cadet training. Thirteen (seven women) Officer Cadets (mean ± SD: age 24 ± 3 years) volunteered to participate. EB and EA were estimated from energy intake (weighing of food and food diaries) and energy expenditure (doubly labeled water) measured in three periods of training: 9 days on-camp (CAMP), a 5-day field exercise (FEX), and a 9-day mixture of both CAMP and field-based training (MIX). Variables were compared by condition and gender with a repeated-measures analysis of variance. Negative EB was greatest during FEX (-2,197 ± 455 kcal/day) compared with CAMP (-692 ± 506 kcal/day; p < .001) and MIX (-1,280 ± 309 kcal/day; p < .001). EA was greatest in CAMP (23 ± 10 kcal·kg free-fat mass [FFM]-1·day-1) compared with FEX (1 ± 16 kcal·kg FFM-1·day-1; p = .002) and MIX (10 ± 7 kcal·kg FFM-1·day-1; p = .003), with no apparent difference between FEX and MIX (p = .071). Irrespective of condition, there were no apparent differences between gender in EB (p = .375) or EA (p = .385). These data can be used to inform evidenced-based strategies to manage EA and EB during military training, and enhance the health and performance of military personnel.
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16
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Beyond a question of liking: Examining military foods using the Best-Worst Scaling technique. Food Qual Prefer 2022. [DOI: 10.1016/j.foodqual.2021.104462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Kitunen A, Carins J, De Diana J. Segments of military ration pack eaters: Choice preferences among groups. Appetite 2022; 174:106023. [PMID: 35364115 DOI: 10.1016/j.appet.2022.106023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 03/23/2022] [Accepted: 03/26/2022] [Indexed: 11/29/2022]
Abstract
Best-Worst Scaling (BWS) has the potential to improve menu design by determining the most and least preferred combat ration pack (CRP) items by military personnel. However, individual differences among large groups means that a ration pack design based on the average of preferences may leave many individuals dissatisfied. This paper extends the existing literature by segmenting Australian military personnel based on the preferences for specific ration pack items. Military personnel (n = 300) provided BWS data via an online survey providing product preferences for 21 items. Participants were randomly allocated to one of four different military scenarios developed and refined by Australian Defence Force (ADF) personnel, ensuring consistency with typical operational and training exercises. The four scenarios were presented with two environment variations (hot/dry or hot/humid) and two resupply variations (daily or resupply on day four and day seven) creating four survey sub-groups. Two-step cluster analysis revealed three military segments (Snackers, Balanced eaters, and Mindful eaters) with distinct CRP item preferences across the larger military group. This study provides insights of the feasibility and usefulness of segmenting military personnel based on ration pack item preferences. This approach could streamline the process for decision makers responsible for designing and developing ration packs, and ultimately increase consumption so that personnel obtain essential nutrition to support their performance.
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Affiliation(s)
- Anna Kitunen
- Social Marketing @ Griffith, Griffith University, 170 Kessels Road, Nathan, QLD, 4111, Australia.
| | - Julia Carins
- Social Marketing @ Griffith, Griffith University, 170 Kessels Road, Nathan, QLD, 4111, Australia.
| | - Jeanine De Diana
- Food and Nutrition, Land Division, Defence Science and Technology, Scottsdale, TAS, 7260, Australia.
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18
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Millet J, Siracusa J, Tardo-Dino PE, Thivel D, Koulmann N, Malgoyre A, Charlot K. Effects of Acute Heat and Cold Exposures at Rest or during Exercise on Subsequent Energy Intake: A Systematic Review and Meta-Analysis. Nutrients 2021; 13:nu13103424. [PMID: 34684424 PMCID: PMC8538265 DOI: 10.3390/nu13103424] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/25/2021] [Accepted: 09/27/2021] [Indexed: 02/06/2023] Open
Abstract
The objective of this meta-analysis was to assess the effect of acute heat/cold exposure on subsequent energy intake (EI) in adults. We searched the following sources for publications on this topic: PubMed, Ovid Medline, Science Direct and SPORTDiscus. The eligibility criteria for study selection were: randomized controlled trials performed in adults (169 men and 30 women; 20–52 years old) comparing EI at one or more meals taken ad libitum, during and/or after exposure to heat/cold and thermoneutral conditions. One of several exercise sessions could be realized before or during thermal exposures. Two of the thirteen studies included examined the effect of heat (one during exercise and one during exercise and at rest), eight investigated the effect of cold (six during exercise and two at rest), and three the effect of both heat and cold (two during exercise and one at rest). The meta-analysis revealed a small increase in EI in cold conditions (g = 0.44; p = 0.019) and a small decrease in hot conditions (g = −0.39, p = 0.022) for exposure during both rest and exercise. Exposures to heat and cold altered EI in opposite ways, with heat decreasing EI and cold increasing it. The effect of exercise remains unclear.
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Affiliation(s)
- Juliette Millet
- Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, 91223 Bretigny-Sur-Orge, France; (J.M.); (J.S.); (P.-E.T.-D.); (N.K.); (A.M.)
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
| | - Julien Siracusa
- Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, 91223 Bretigny-Sur-Orge, France; (J.M.); (J.S.); (P.-E.T.-D.); (N.K.); (A.M.)
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
| | - Pierre-Emmanuel Tardo-Dino
- Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, 91223 Bretigny-Sur-Orge, France; (J.M.); (J.S.); (P.-E.T.-D.); (N.K.); (A.M.)
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
| | - David Thivel
- Laboratory AME2P, University of Clermont Auvergne, 63170 Aubière, France;
| | - Nathalie Koulmann
- Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, 91223 Bretigny-Sur-Orge, France; (J.M.); (J.S.); (P.-E.T.-D.); (N.K.); (A.M.)
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
- Ecole du Val-de-Grâce, 1, Place Alphonse Laveran, 75230 Paris, France
| | - Alexandra Malgoyre
- Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, 91223 Bretigny-Sur-Orge, France; (J.M.); (J.S.); (P.-E.T.-D.); (N.K.); (A.M.)
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
| | - Keyne Charlot
- Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, 91223 Bretigny-Sur-Orge, France; (J.M.); (J.S.); (P.-E.T.-D.); (N.K.); (A.M.)
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
- Correspondence: ; Tel.: +33-(1)78-65-13-03
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19
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Wardle SL, O'Leary TJ, McClung JP, Pasiakos SM, Greeves JP. Feeding female soldiers: Consideration of sex-specific nutrition recommendations to optimise the health and performance of military personnel. J Sci Med Sport 2021; 24:995-1001. [PMID: 34452842 DOI: 10.1016/j.jsams.2021.08.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 06/25/2021] [Accepted: 08/11/2021] [Indexed: 12/25/2022]
Abstract
Appropriate nutrition recommendations are required to optimise the health and performance of military personnel, yet limited data are available on whether male and female military personnel have different nutrition requirements. OBJECTIVES To consider the evidence for sex-specific nutrition requirements to optimise the health and performance of military personnel. DESIGN Narrative review. METHODS Published literature was reviewed, with a focus on sex-specific requirements, in the following areas: nutrition for optimising muscle mass and function, nutrition during energy deficit, and nutrition for reproductive and bone health. RESULTS There are limited data on sex differences in protein requirements but extant data suggest that, despite less muscle mass, on average, in women, sex-specific protein feeding strategies are not required to optimise muscle mass in military-aged individuals. Similarly, despite sex differences in metabolic and endocrine responses to energy deficit, current data do not suggest a requirement for sex-specific feeding strategies during energy deficit. Energy deficit impairs health and performance, most notably bone and reproductive health and these impairments are greater for women. Vitamin D, iron and calcium are important nutrients to protect the bone health of female military personnel due to increased risk of stress fracture. CONCLUSIONS Women have an increased incidence of bone injuries, less muscle mass and are more susceptible to the negative effects of energy deficit, including compromised reproductive health. However, there are limited data on sex differences in response to various nutrition strategies designed to improve these elements of health and performance. Future studies should evaluate whether sex-specific feeding recommendations are required.
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Affiliation(s)
- Sophie L Wardle
- Army Health and Performance Research, Army Headquarters, United Kingdom; Division of Surgery and Interventional Science, University College London, United Kingdom.
| | - Thomas J O'Leary
- Army Health and Performance Research, Army Headquarters, United Kingdom; Division of Surgery and Interventional Science, University College London, United Kingdom
| | - James P McClung
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, United States of America
| | - Stefan M Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, United States of America
| | - Julie P Greeves
- Army Health and Performance Research, Army Headquarters, United Kingdom; Division of Surgery and Interventional Science, University College London, United Kingdom; Norwich Medical School, University of East Anglia, United Kingdom
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20
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Gan LSH, Fan PWP, Zhang J, Nolte HW, Friedl KE, Nindl BC, Lee JKW. Changes in energy balance, body composition, metabolic profile and physical performance in a 62-day Army Ranger training in a hot-humid environment. J Sci Med Sport 2021; 25:89-94. [PMID: 34507882 DOI: 10.1016/j.jsams.2021.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 08/01/2021] [Accepted: 08/04/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVES To determine the physiological effects of multiple stressors including energy deficit during a 62-day Ranger course in a hot-humid environment. DESIGN Prospective cohort design. METHODS Food intake data were collected daily and energy expenditure at each of the three phases of the course was estimated by the doubly-labeled water method. Anthropometry, hydration status, stress and metabolic hormones, handgrip strength and lower explosive power were measured at the start and at the end of each phase. RESULTS Seventeen male participants (age: 24.5 ± 3.2 years, height: 173.9 ± 5.1 cm, body mass: 69.3 ± 3.2 kg, BMI: 22.9 ± 0.9 kg/m2, percent body fat: 14 ± 5%) completed the study. Mean total daily energy expenditure was 4756 kcal/day and mean daily energy intake was 3882 kcal/day. An 18% energy deficit resulted in an average body mass loss of 4.6 kg, comprising mostly fat mass. Participants with higher baseline adiposity (>15% body fat) lost more fat mass and gained (rather than lost) muscle mass compared to those with lower baseline adiposity. Handgrip strength declined only at the end of Phase I, while lower body explosive power declined progressively throughout the course. Lean mass in arms and legs was correlated with initial grip strength and lower body explosive power, but only at the start of the course. CONCLUSIONS Physiologically demanding Ranger training in an equatorial environment is at least as metabolically demanding and stressful as other similar high-risk training courses, as demonstrated by the stress and metabolic endocrine responses, changes in body composition, and reduction in explosive power. Moreover, the smaller body size of Asian soldiers may confer an energetic advantage over larger sized Western counterparts.
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Affiliation(s)
- Linda S H Gan
- Combat Protection and Performance Programme, Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore
| | - Priscilla W P Fan
- Combat Protection and Performance Programme, Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore
| | - Junren Zhang
- Army Medical Services, Singapore Armed Forces, Singapore
| | - Heinrich W Nolte
- Movement Physiology Research Laboratory, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, South Africa
| | - Karl E Friedl
- U.S. Army Research Institute of Environmental Medicine, United States
| | - Bradley C Nindl
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, University of Pittsburgh, United States
| | - Jason K W Lee
- Human Potential Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Global Asia Institute, National University of Singapore, Singapore; N.1 Institute for Health, National University of Singapore, Singapore; Institute for Digital Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR), Singapore.
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21
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Varanoske AN, Harris MN, Hebert C, Howard EE, Johannsen NM, Heymsfield SB, Greenway FL, Margolis LM, Lieberman HR, Church DD, Ferrando AA, Rood JC, Pasiakos SM. Effects of testosterone undecanoate on performance during multi-stressor military operations: A trial protocol for the Optimizing Performance for Soldiers II study. Contemp Clin Trials Commun 2021; 23:100819. [PMID: 34278044 PMCID: PMC8264529 DOI: 10.1016/j.conctc.2021.100819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 06/15/2021] [Accepted: 07/02/2021] [Indexed: 11/22/2022] Open
Abstract
Background Previously, young males administered 200 mg/week of testosterone enanthate during 28 days of energy deficit (EDef) gained lean mass and lost less total mass than controls (Optimizing Performance for Soldiers I study, OPS I). Despite that benefit, physical performance deteriorated similarly in both groups. However, some experimental limitations may have precluded detection of performance benefits, as performance measures employed lacked military relevance, and the EDef employed did not elicit the magnitude of stress typically experienced by Soldiers conducting operations. Additionally, the testosterone administered required weekly injections, elicited supra-physiological concentrations, and marked suppression of endogenous testosterone upon cessation. Therefore, this follow-on study will address those limitations and examine testosterone's efficacy for preserving Solder performance during strenuous operations. Methods In OPS II, 32 males will participate in a randomized, placebo-controlled, double-blind trial. After baseline testing, participants will be administered either testosterone undecanoate (750 mg) or placebo before completing four consecutive, 5-day cycles simulating a multi-stressor, sustained military operation (SUSOPS). SUSOPS will consist of two low-stress days (1000 kcal/day exercise-induced EDef; 8 h/night sleep), followed by three high-stress days (3000 kcal/day and 4 h/night). A 23-day recovery period will follow SUSOPS. Military relevant physical performance is the primary outcome. Secondary outcomes include 4-comparment body composition, muscle and whole-body protein turnover, intramuscular mechanisms, biochemistries, and cognitive function/mood. Conclusions OPS II will determine if testosterone undecanoate safely enhances performance, while attenuating muscle and total mass loss, without impairing cognitive function, during and in recovery from SUSOPS. Trial Registration ClinicalTrials.gov Identifier: NCT04120363.
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Key Words
- Anabolism
- And hypogonadism
- BIA, bioelectrical impedance analysis
- D2O, deuterium
- DSMB, data and safety monitoring board
- DXA, dual-energy x-ray absorptiometry
- ECW, extracellular water
- EDef, energy deficit
- EIEE, exercise-induced energy expenditure
- Energy deficit
- Exercise
- FBR, fractional breakdown rate
- FFM, fat-free mass
- FSR, fractional synthetic rate
- HR, heart rate
- HRR, heart rate reserve
- ICW, intracellular water
- ID, identification
- IRB, Institutional Review Board
- MRE, Meal
- Optimizing Performance for Soldiers Trial I, OPS II
- Optimizing Performance for Soldiers Trial II, PAR-Q+
- Pennington Biomedical Research Center, PLA
- Physical Activity Readiness Questionnaire+, PB
- Ready-to-Eat, OPS I
- Skeletal muscle
- Sleep deprivation
- TBW, total body water
- TDEE, total daily energy expenditure
- TDEI, total daily energy intake
- TEST, testosterone experimental group
- VO2max, maximal cardiorespiratory fitness
- VO2peak, peak oxygen uptake
- WBGT, wet bulb globe temperature
- placebo experimental group, PS
- protein breakdown, PBRC
- protein synthesis, Q
- ratings of perceived exertion, SUSOPS
- repetition maximum, RNA
- respiratory exchange ratio, RM
- ribonucleic acid, RPE
- sustained, multi-stressor military operations
- whole-body nitrogen flux, RER
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Affiliation(s)
- Alyssa N Varanoske
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Melissa N Harris
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Callie Hebert
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Emily E Howard
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Neil M Johannsen
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Steven B Heymsfield
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Frank L Greenway
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Harris R Lieberman
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - David D Church
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Arny A Ferrando
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Jennifer C Rood
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
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22
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Coleman JL, Carrigan CT, Margolis LM. Body composition changes in physically active individuals consuming ketogenic diets: a systematic review. J Int Soc Sports Nutr 2021; 18:41. [PMID: 34090453 PMCID: PMC8180141 DOI: 10.1186/s12970-021-00440-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 05/11/2021] [Indexed: 12/28/2022] Open
Abstract
Background To achieve ideal strength/power to mass ratio, athletes may attempt to lower body mass through reductions in fat mass (FM), while maintaining or increasing fat-free mass (FFM) by manipulating their training regimens and diets. Emerging evidence suggests that consumption of high-fat, ketogenic diets (KD) may be advantageous for reducing body mass and FM, while retaining FFM. Methods A systematic review of the literature was conducted using PubMed and Cochrane Library databases to compare the effects of KD versus control diets (CON) on body mass and composition in physically active populations. Randomized and non-randomized studies were included if participants were healthy (free of chronic disease), physically active men or women age ≥ 18 years consuming KD (< 50 g carbohydrate/d or serum or whole blood β-hydroxybutyrate (βhb) > 0.5 mmol/L) for ≥14 days. Results Thirteen studies (9 parallel and 4 crossover/longitudinal) that met the inclusion criteria were identified. Aggregated results from the 13 identified studies show body mass decreased 2.7 kg in KD and increased 0.3 kg in CON. FM decreased by 2.3 kg in KD and 0.3 kg in CON. FFM decreased by 0.3 kg in KD and increased 0.7 kg in CON. Estimated energy balance based on changes in body composition was − 339 kcal/d in KD and 5 kcal/d in CON. Risk of bias identified some concern of bias primarily due to studies which allowed participants to self-select diet intervention groups, as well as inability to blind participants to the study intervention, and/or longitudinal study design. Conclusion KD can promote mobilization of fat stores to reduce FM while retaining FFM. However, there is variance in results of FFM across studies and some risk-of-bias in the current literature that is discussed in this systematic review. Supplementary Information The online version contains supplementary material available at 10.1186/s12970-021-00440-6.
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Affiliation(s)
- Julie L Coleman
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Building 42, Natick, MA, 01760, USA.,Oak Ridge Institute of Science and Education, Belcamp, MD, USA
| | - Christopher T Carrigan
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Building 42, Natick, MA, 01760, USA
| | - Lee M Margolis
- U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave, Building 42, Natick, MA, 01760, USA.
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23
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Karl JP, Margolis LM, Fallowfield JL, Child RB, Martin NM, McClung JP. Military nutrition research: Contemporary issues, state of the science and future directions. Eur J Sport Sci 2021; 22:87-98. [PMID: 33980120 DOI: 10.1080/17461391.2021.1930192] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The importance of diet and nutrition to military readiness and performance has been recognized for centuries as dietary nutrients sustain health, protect against illness, and promote resilience, performance and recovery. Contemporary military nutrition research is increasingly inter-disciplinary with emphasis often placed on the broad topics of (1) determining operational nutrition requirements in all environments, (2) characterizing nutritional practices of military personnel relative to the required (role/environment) standards, and (3) developing strategies for improving nutrient delivery and individual choices. This review discusses contemporary issues shared internationally by military nutrition research programmes, and highlights emerging topics likely to influence future military nutrition research and policy. Contemporary issues include improving the diet quality of military personnel, optimizing operational rations, and increasing understanding of biological factors influencing nutrient requirements. Emerging areas include the burgeoning field of precision nutrition and its technological enablers.
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Affiliation(s)
- J Philip Karl
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Lee M Margolis
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Joanne L Fallowfield
- Environmental Medicine and Science Division, Institute of Naval Medicine, Alverstoke, Hampshire, UK
| | - Robert B Child
- School of Chemical Engineering, University of Birmingham, Birmingham, UK
| | - Nicola M Martin
- New Zealand Army, New Zealand Defence Force, Upper Hutt, New Zealand
| | - James P McClung
- Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA, USA
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24
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Charlot K, Chapelot D, Siracusa J, Lavoué C, Colin P, Oustric P, Thivel D, Finlayson G, Bourrilhon C. An augmented food strategy leads to complete energy compensation during a 15-day military training expedition in the cold. Physiol Rep 2021; 9:e14591. [PMID: 34057319 PMCID: PMC8165736 DOI: 10.14814/phy2.14591] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/03/2020] [Accepted: 09/03/2020] [Indexed: 12/20/2022] Open
Abstract
Soldiers on military expeditions usually fail to compensate for the increase in energy expenditure, with potential deleterious consequences. We therefore analyzed the characteristics of energy compensation in 12 male soldiers, during a 15-day expedition in the cold, while alleviating some of the contextual limitations of food intake (~20-MJ daily bags of easy-to-use, highly palatable and familiar foods with multiple and long breaks allowed during the day). Body and fat mass losses were low and moderate, respectively (-1.13 ± 1.42% and -19.5 ± 15.6%, respectively, p < .021). Mean energy intake (EI) was high (~16.3 MJ) and increased at each third of the expedition (15.3 ± 2.1, 16.1 ± 2.1, and 17.6 ± 2.0 for D1-5, D6-10 and D11-15, respectively, p < .012). This resulted in reaching a neutral energy balance as soon as the D6 to 10 period and reaching normal energy availability during D11 to 15. Participants only increased their EI during the mid-day (10:00-14:00) period (p = .002) whereas hunger and thirst only increased in the morning, with higher scores during D11-15 than D1-5 (p < .009). Last, the reward value of sweet foods was also higher during D11-15 than during D1-5 (p = .026). The changes in body mass were positively associated with EI (r = 0.598, p = .040) and carbohydrate intake (r = 0.622, p = .031). This study indicates that complete energy compensation can be reached in challenging field conditions when food intake is facilitated, offering some guidelines to limit energy deficit during operational missions.
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Affiliation(s)
- Keyne Charlot
- Unité de Physiologie de l'Exercice et des Activités en Conditions ExtrêmesDépartement Environnements OpérationnelsInstitut de Recherche Biomédicale des ArméesBretigny‐Sur‐OrgeFrance
- LBEPSUniv EvryIRBAUniversité Paris SaclayEvryFrance
| | - Didier Chapelot
- Centre de Recherche en Epidémiologie et StatistiqueEquipe de Recherche en Epidémiologie Nutritionnelle (EREN)Inserm (U1153)Inra (U1125)CnamUniversité Paris 13BobignyFrance
| | - Julien Siracusa
- Unité de Physiologie de l'Exercice et des Activités en Conditions ExtrêmesDépartement Environnements OpérationnelsInstitut de Recherche Biomédicale des ArméesBretigny‐Sur‐OrgeFrance
- LBEPSUniv EvryIRBAUniversité Paris SaclayEvryFrance
| | - Chloé Lavoué
- Unité de Physiologie de l'Exercice et des Activités en Conditions ExtrêmesDépartement Environnements OpérationnelsInstitut de Recherche Biomédicale des ArméesBretigny‐Sur‐OrgeFrance
- LBEPSUniv EvryIRBAUniversité Paris SaclayEvryFrance
| | - Philippe Colin
- Unité de Physiologie de l'Exercice et des Activités en Conditions ExtrêmesDépartement Environnements OpérationnelsInstitut de Recherche Biomédicale des ArméesBretigny‐Sur‐OrgeFrance
- LBEPSUniv EvryIRBAUniversité Paris SaclayEvryFrance
| | - Pauline Oustric
- Appetite Control Energy Balance Research GroupSchool of PsychologyFaculty of Medicine and HealthUniversity of LeedsLeedsUnited Kingdom
| | - David Thivel
- Appetite Control Energy Balance Research GroupSchool of PsychologyFaculty of Medicine and HealthUniversity of LeedsLeedsUnited Kingdom
- Laboratoire des adaptations Métaboliques à l’Exercice en conditions Physiologiques et Pathologiques (EA 3533)Université Clermont AuvergneClermont‐FerrandFrance
| | - Graham Finlayson
- Appetite Control Energy Balance Research GroupSchool of PsychologyFaculty of Medicine and HealthUniversity of LeedsLeedsUnited Kingdom
| | - Cyprien Bourrilhon
- Unité de Physiologie de l'Exercice et des Activités en Conditions ExtrêmesDépartement Environnements OpérationnelsInstitut de Recherche Biomédicale des ArméesBretigny‐Sur‐OrgeFrance
- LBEPSUniv EvryIRBAUniversité Paris SaclayEvryFrance
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25
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Radcliffe PN, Whitney CC, Fagnant HS, Wilson MA, Finlayson G, Smith TJ, Karl JP. Severe sleep restriction suppresses appetite independent of effects on appetite regulating hormones in healthy young men without obesity. Physiol Behav 2021; 237:113438. [PMID: 33940082 DOI: 10.1016/j.physbeh.2021.113438] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Several nights of moderate (4-5 hr/night) sleep restriction increases appetite and energy intake, and may alter circulating concentrations of appetite regulating hormones. Whether more severe sleep restriction has similar effects is unclear. This study aimed to determine the effects of severe, short-term sleep restriction on appetite, ad libitum energy intake during a single meal, appetite regulating hormones, and food preferences. METHODS Randomized, crossover study in which 18 healthy men (mean ± SD: BMI 24.4 ± 2.3 kg/m2, 20 ± 2 yr) were assigned to three consecutive nights of sleep restriction (SR; 2 hr sleep opportunity/night) or adequate sleep (AS; 7-9 hr sleep opportunity/night) with controlled feeding and activity designed to maintain energy balance throughout the 3-day period. On day 4, participants consumed a standardized breakfast. Appetite, assessed by visual analogue scales, and circulating ghrelin, peptide-YY (PYY), glucagon-like peptide (GLP-1), insulin, and glucose concentrations were measured before and every 20-60 min for 4hr after the meal. Ad libitum energy and macronutrient intakes were then measured at a provided buffet lunch. Food preferences were measured by Leeds Food Preference Questionnaire (LFPQ) administered before and after the lunch. RESULTS Area under the curve (AUC) of postprandial hunger (-23%), desire to eat (-23%), and prospective consumption (-18%) ratings were all lower, and postprandial fullness AUC (25%) was higher after SR relative to after AS (p ≤ 0.02). Ad libitum energy intake at the lunch meal was 332 kcal [95% CI: -479, -185] (p<0.001) lower after SR relative to after AS, but relative macronutrient intakes and LFPQ scores did not differ. Postprandial glucose, insulin, PYY, GLP-1, and ghrelin AUCs did not differ between phases. However, mean concentrations of PYY (-11%) and GLP-1 (-4%) over the 4-hr testing period were lower, and glucose concentrations were 6% higher, after SR relative to after AS (p ≤ 0.01). CONCLUSION In contrast with reported effects of moderate sleep restriction, severe sleep restriction reduced appetite and energy intake, had no impact food preferences, and had little impact on appetite regulating hormones. Findings suggest that severe sleep restriction may suppress appetite and food intake, at least at a single meal, by a mechanism independent of changes in food preference or appetite regulating hormones.
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Affiliation(s)
- Patrick N Radcliffe
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA; Oak Ridge Institute of Science and Education, Oak Ridge, TN, USA
| | - Claire C Whitney
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Heather S Fagnant
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Marques A Wilson
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Graham Finlayson
- Oak Ridge Institute of Science and Education, Oak Ridge, TN, USA; School of psychology, University of Leeds, Leeds, UK
| | - Tracey J Smith
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - J Philip Karl
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA.
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26
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Negative energy balance during military training: The role of contextual limitations. Appetite 2021; 164:105263. [PMID: 33862189 DOI: 10.1016/j.appet.2021.105263] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 02/09/2021] [Accepted: 04/09/2021] [Indexed: 12/25/2022]
Abstract
During multiday training exercises, soldiers almost systematically face a moderate-to-large energy deficit, affecting their body mass and composition and potentially their physical and cognitive performance. Such energy deficits are explained by their inability to increase their energy intake during these highly demanding periods. With the exception of certain scenarios in which rations are voluntarily undersized to maximize the constraints, the energy content of the rations are often sufficient to maintain a neutral energy balance, suggesting that other limitations are responsible for such voluntary and/or spontaneous underconsumption. In this review, the overall aim was to present an overview of the impact of military training on energy balance, a context that stands out by its summation of specific limitations that interfere with energy intake. We first explore the impact of military training on the various components of energy balance (intake and expenditure) and body mass loss. Then, the role of the dimensioning of the rations (total energy content above or below energy expenditure) on energy deficits are addressed. Finally, the potential limitations inherent to military training (training characteristics, food characteristics, timing and context of eating, and the soldiers' attitude) are discussed to identify potential strategies to spontaneously increase energy intake and thus limit the energy deficit.
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27
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Scott JPR, Kramer A, Petersen N, Green DA. The Role of Long-Term Head-Down Bed Rest in Understanding Inter-Individual Variation in Response to the Spaceflight Environment: A Perspective Review. Front Physiol 2021; 12:614619. [PMID: 33643065 PMCID: PMC7904881 DOI: 10.3389/fphys.2021.614619] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 01/04/2021] [Indexed: 12/12/2022] Open
Abstract
Exposure to the spaceflight environment results in profound multi-system physiological adaptations in which there appears to be substantial inter-individual variability (IV) between crewmembers. However, performance of countermeasure exercise renders it impossible to separate the effects of the spaceflight environment alone from those associated with exercise, whilst differences in exercise programs, spaceflight operations constraints, and environmental factors further complicate the interpretation of IV. In contrast, long-term head-down bed rest (HDBR) studies isolate (by means of a control group) the effects of mechanical unloading from those associated with countermeasures and control many of the factors that may contribute to IV. In this perspective, we review the available evidence of IV in response to the spaceflight environment and discuss factors that complicate its interpretation. We present individual data from two 60-d HDBR studies that demonstrate that, despite the highly standardized experimental conditions, marked quantitative differences still exist in the response of the cardiorespiratory and musculoskeletal systems between individuals. We also discuss the statistical concept of “true” and “false” individual differences and its potential application to HDBR data. We contend that it is currently not possible to evaluate IV in response to the spaceflight environment and countermeasure exercise. However, with highly standardized experimental conditions and the presence of a control group, HDBR is suitable for the investigation of IV in the physiological responses to gravitational unloading and countermeasures. Such investigations may provide valuable insights into the potential role of IV in adaptations to the spaceflight environment and the effectiveness of current and future countermeasures.
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Affiliation(s)
- Jonathan P R Scott
- Space Medicine Team, ISS Operations and Astronaut Group, Directorate of Human and Robotic Exploration, European Space Agency, Cologne, Germany.,KBR GmbH, Cologne, Germany
| | - Andreas Kramer
- Department of Sport Science, University of Konstanz, Konstanz, Germany
| | - Nora Petersen
- Space Medicine Team, ISS Operations and Astronaut Group, Directorate of Human and Robotic Exploration, European Space Agency, Cologne, Germany.,KBR GmbH, Cologne, Germany
| | - David A Green
- Space Medicine Team, ISS Operations and Astronaut Group, Directorate of Human and Robotic Exploration, European Space Agency, Cologne, Germany.,KBR GmbH, Cologne, Germany.,Centre of Human and Applied Physiology, King's College London, London, United Kingdom
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28
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Effects of energy balance on appetite and physiological mediators of appetite during strenuous physical activity: secondary analysis of a randomised crossover trial. Br J Nutr 2021; 126:1571-1584. [DOI: 10.1017/s0007114521000131] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Abstract
Energy deficit is common during prolonged periods of strenuous physical activity and limited sleep, but the extent to which appetite suppression contributes is unclear. The aim of this randomised crossover study was to determine the effects of energy balance on appetite and physiological mediators of appetite during a 72-h period of high physical activity energy expenditure (about 9·6 MJ/d (2300 kcal/d)) and limited sleep designed to simulate military operations (SUSOPS). Ten men consumed an energy-balanced diet while sedentary for 1 d (REST) followed by energy-balanced (BAL) and energy-deficient (DEF) controlled diets during SUSOPS. Appetite ratings, gastric emptying time (GET) and appetite-mediating hormone concentrations were measured. Energy balance was positive during BAL (18 (sd 20) %) and negative during DEF (–43 (sd 9) %). Relative to REST, hunger, desire to eat and prospective consumption ratings were all higher during DEF (26 (sd 40) %, 56 (sd 71) %, 28 (sd 34) %, respectively) and lower during BAL (–55 (sd 25) %, −52 (sd 27) %, −54 (sd 21) %, respectively; Pcondition < 0·05). Fullness ratings did not differ from REST during DEF, but were 65 (sd 61) % higher during BAL (Pcondition < 0·05). Regression analyses predicted hunger and prospective consumption would be reduced and fullness increased if energy balance was maintained during SUSOPS, and energy deficits of ≥25 % would be required to elicit increases in appetite. Between-condition differences in GET and appetite-mediating hormones identified slowed gastric emptying, increased anorexigenic hormone concentrations and decreased fasting acylated ghrelin concentrations as potential mechanisms of appetite suppression. Findings suggest that physiological responses that suppress appetite may deter energy balance from being achieved during prolonged periods of strenuous activity and limited sleep.
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29
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McClung HL, Armstrong NJ, Hennigar SR, Staab JS, Montain SJ, Karl J. Randomized Trial Comparing Consumption of Military Rations to Usual Intake for 21 Consecutive Days: Nutrient Adequacy and Indicators of Health Status. J Acad Nutr Diet 2020; 120:1791-1804. [DOI: 10.1016/j.jand.2020.06.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/15/2020] [Accepted: 06/18/2020] [Indexed: 12/17/2022]
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30
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Abstract
Objective: The purpose of this study was to evaluate pre- and postseason measures of body composition, skeletal muscle, and blood parameters/liver lipid in wildland firefighters (WLFF) over the fire season. Methods: Alaskan WLFF (N = 27) crews were evaluated pre- and postwildfire season, which included 63 ± 10 operational days. Body composition, thigh muscle area, and liver lipid were quantified using dual-energy radiograph absorptiometry and magnetic resonance imaging, respectively. Blood metabolic and lipid panels were also collected and analyzed. Results: Total body, fat, and visceral fat mass increased from pre- to postseason (P < 0.05). Total cholesterol, LDL, and total globulin also increased (P < 0.05). There was a trend (P = 0.06) towards an increase in intrahepatic lipid. Conclusions: The observed maladaptive changes in adipose tissue, blood lipids, and hepatic function may reflect adaptations/consequences to occupational demands/conditions and warrant evaluation of appropriate countermeasures.
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The Influence of Training on New Army Recruits’ Energy and Macronutrient Intakes and Performance: A Systematic Literature Review. J Acad Nutr Diet 2020; 120:1687-1705. [DOI: 10.1016/j.jand.2020.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 05/28/2020] [Accepted: 06/04/2020] [Indexed: 12/22/2022]
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Charlot K, Chapelot D, Colin P, Bourrilhon C. Daily energy balance and eating behaviour during a 14-day cold weather expedition in Greenland. Appl Physiol Nutr Metab 2020; 45:968-977. [DOI: 10.1139/apnm-2019-0677] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We assessed energy compensation, appetite, and reward value of foods during a 14-day military expedition in Greenland realized by 12 male French soldiers, during which energy compensation was optimized by providing them with easy-to-eat palatable foods in excess. Although daily energy expenditure (estimated by accelerometry) stayed relatively constant throughout the expedition (15 ± 9 MJ·day−1), energy intake (EI; estimated by self-reported diaries) was 17% higher during the D8–D14 period compared with the D1–D7 period, leading to a neutral energy balance (EB). Body fat mass (BFM) significantly decreased (–1.0 ± 0.7 kg, p < 0.001) but not body mass (BM). Neither hunger scores (assessed by visual analog scales) nor components of the reward value of food (explicit liking (EL) and food preference) were significantly altered. However, changes in EL at D10 were positively correlated with changes in BM (r = 0.600, p < 0.05) and BFM (r = 0.680, p < 0.05) and changes in hunger in the EI of the relevant period (r = 0.743, p < 0.01 for D1–D7, r = 0.652, p < 0.05 for D8–14). This study shows that the negative EB and BM loss can be attenuated by an appropriate food supply and that subjective components of eating behaviour, such as hunger and EL, may be useful to predict the magnitude of energy compensation. Novelty Energy intake increases during of a 14-day expedition in the cold. Energy compensation was likely facilitated by providing participants with easy-to-eat palatable and familiar foods. Hunger scores and EL for energy-dense foods were associated with high EIs and low BM changes.
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Affiliation(s)
- Keyne Charlot
- Institut de Recherche Biomédicale des Armées, Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, 1 place Général Valérie André, 91223 Bretigny-Sur-Orge, France
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
| | - Didier Chapelot
- Université Paris 13, Centre de Recherche en Epidémiologie et Statistique, Equipe de Recherche en Epidémiologie Nutritionnelle (EREN), Inserm (U1153), Inra (U1125), Cnam, Bobigny, France
| | - Philippe Colin
- Institut de Recherche Biomédicale des Armées, Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, 1 place Général Valérie André, 91223 Bretigny-Sur-Orge, France
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
| | - Cyprien Bourrilhon
- Institut de Recherche Biomédicale des Armées, Unité de Physiologie des Exercices et Activités en Conditions Extrêmes, Département Environnements Opérationnels, 1 place Général Valérie André, 91223 Bretigny-Sur-Orge, France
- LBEPS, Univ Evry, IRBA, Université Paris Saclay, 91025 Evry, France
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Murphy NE, Carrigan CT, Margolis LM. High-Fat Ketogenic Diets and Physical Performance: A Systematic Review. Adv Nutr 2020; 12:223-233. [PMID: 32865567 PMCID: PMC7850028 DOI: 10.1093/advances/nmaa101] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/13/2020] [Accepted: 07/28/2020] [Indexed: 12/15/2022] Open
Abstract
Use of high-fat, ketogenic diets (KDs) to support physical performance has grown in popularity over recent years. While these diets enhance fat and reduce carbohydrate oxidation during exercise, the impact of a KD on physical performance remains controversial. The objective of this work was to assess the effect of KDs on physical performance compared with mixed macronutrient diets [control (CON)]. A systematic review of the literature was conducted using PubMed and Cochrane Library databases. Randomized and nonrandomized studies were included if participants were healthy (free of chronic disease), nonobese [BMI (kg/m2) <30], trained or untrained men or women consuming KD (<50 g carbohydrate/d or serum or whole-blood β-hydroxybutyrate >0.5 mmol/L) compared with CON (fat, 12-38% of total energy intake) diets for ≥14 d, followed by a physical performance test. Seventeen studies (10 parallel, 7 crossover) with 29 performance (13 endurance, 16 power or strength) outcomes were identified. Of the 13 endurance-type performance outcomes, 3 (1 time trial, 2 time-to-exhaustion) reported lower and 10 (4 time trials, 6 time-to-exhaustion) reported no difference in performance between the KD compared with CON. Of the 16 power or strength performance outcomes, 3 (1 power, 2 strength) reported lower, 11 (4 power, 7 strength) no difference, and 2 (power) enhanced performance in the KD compared with the CON. Risk of bias identified some concern of bias primarily due to studies allowing participants to self-select diet intervention groups and the inability to blind participants to the study intervention. Overall, the majority of null results across studies suggest that a KD does not have a positive or negative impact on physical performance compared with a CON diet. However, discordant results between studies may be due to multiple factors, such as the duration consuming study diets, training status, performance test, and sex differences, which will be discussed in this systematic review.
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Affiliation(s)
- Nancy E Murphy
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Christopher T Carrigan
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
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O'Leary TJ, Wardle SL, Greeves JP. Energy Deficiency in Soldiers: The Risk of the Athlete Triad and Relative Energy Deficiency in Sport Syndromes in the Military. Front Nutr 2020; 7:142. [PMID: 32984399 PMCID: PMC7477333 DOI: 10.3389/fnut.2020.00142] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/21/2020] [Indexed: 12/15/2022] Open
Abstract
Military personnel experience energy deficit (total energy expenditure higher than energy intake), particularly during combat training and field exercises where exercising energy expenditures are high and energy intake is reduced. Low energy availability (energy intake minus exercising energy expenditure expressed relative to fat free mass) impairs endocrine function and bone health, as recognized in female athletes as the Female Athlete Triad syndrome. More recently, the Relative Energy Deficiency in Sport (RED-S) syndrome encompasses broader health outcomes, physical and cognitive performance, non-athletes, and men. This review summarizes the evidence for the effect of low energy availability and energy deficiency in military training and operations on health and performance outcomes. Energy availability is difficult to measure in free-living individuals but doubly labeled water studies demonstrate high total energy expenditures during military training; studies that have concurrently measured energy intake, or measured body composition changes with DXA, suggest severe and/or prolonged energy deficits. Military training in energy deficit disturbs endocrine and metabolic function, menstrual function, bone health, immune function, gastrointestinal health, iron status, mood, and physical and cognitive performance. There are more data for men than women, and little evidence on the chronic effects of repeated exposures to energy deficit. Military training impairs indices of health and performance, indicative of the Triad and RED-S, but the multi-stressor environment makes it difficult to isolate the independent effects of energy deficiency. Studies supplementing with energy to attenuate the energy deficit suggest an independent effect of energy deficiency in the disturbances to metabolic, endocrine and immune function, and physical performance, but randomized controlled trials are lacking.
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Affiliation(s)
- Thomas J O'Leary
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, UCL, London, United Kingdom
| | - Sophie L Wardle
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, UCL, London, United Kingdom
| | - Julie P Greeves
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, UCL, London, United Kingdom.,Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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Gwin JA, Church DD, Wolfe RR, Ferrando AA, Pasiakos SM. Muscle Protein Synthesis and Whole-Body Protein Turnover Responses to Ingesting Essential Amino Acids, Intact Protein, and Protein-Containing Mixed Meals with Considerations for Energy Deficit. Nutrients 2020; 12:nu12082457. [PMID: 32824200 PMCID: PMC7469068 DOI: 10.3390/nu12082457] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/07/2020] [Accepted: 08/13/2020] [Indexed: 02/07/2023] Open
Abstract
Protein intake recommendations to optimally stimulate muscle protein synthesis (MPS) are derived from dose-response studies examining the stimulatory effects of isolated intact proteins (e.g., whey, egg) on MPS in healthy individuals during energy balance. Those recommendations may not be adequate during periods of physiological stress, specifically the catabolic stress induced by energy deficit. Providing supplemental intact protein (20–25 g whey protein, 0.25–0.3 g protein/kg per meal) during strenuous military operations that elicit severe energy deficit does not stimulate MPS-associated anabolic signaling or attenuate lean mass loss. This occurs likely because a greater proportion of the dietary amino acids consumed are targeted for energy-yielding pathways, whole-body protein synthesis, and other whole-body essential amino acid (EAA)-requiring processes than the proportion targeted for MPS. Protein feeding formats that provide sufficient energy to offset whole-body energy and protein-requiring demands during energy deficit and leverage EAA content, digestion, and absorption kinetics may optimize MPS under these conditions. Understanding the effects of protein feeding format-driven alterations in EAA availability and subsequent changes in MPS and whole-body protein turnover is required to design feeding strategies that mitigate the catabolic effects of energy deficit. In this manuscript, we review the effects, advantages, disadvantages, and knowledge gaps pertaining to supplemental free-form EAA, intact protein, and protein-containing mixed meal ingestion on MPS. We discuss the fundamental role of whole-body protein balance and highlight the importance of comprehensively assessing whole-body and muscle protein kinetics when evaluating the anabolic potential of varying protein feeding formats during energy deficit.
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Affiliation(s)
- Jess A. Gwin
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA;
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - David D. Church
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (D.D.C); (R.R.W.); (A.A.F.)
| | - Robert R. Wolfe
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (D.D.C); (R.R.W.); (A.A.F.)
| | - Arny A. Ferrando
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (D.D.C); (R.R.W.); (A.A.F.)
| | - Stefan M. Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA;
- Correspondence: ; Tel.: +1-508-206-2353
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Effects of high versus standard essential amino acid intakes on whole-body protein turnover and mixed muscle protein synthesis during energy deficit: A randomized, crossover study. Clin Nutr 2020; 40:767-777. [PMID: 32768315 DOI: 10.1016/j.clnu.2020.07.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 07/07/2020] [Accepted: 07/10/2020] [Indexed: 01/01/2023]
Abstract
BACKGROUND & AIMS Consuming 0.10-0.14 g essential amino acids (EAA)/kg/dose (0.25-0.30 g protein/kg/dose) maximally stimulates muscle protein synthesis (MPS) during energy balance. Whether consuming EAA beyond that amount enhances MPS and whole-body anabolism following energy deficit is unknown. The aims of this study were to determine the effects of standard and high EAA ingestion on mixed MPS and whole-body protein turnover following energy deficit. DESIGN Nineteen males (mean ± SD; 23 ± 5 y; 25.4 ± 2.7 kg/m2) completed a randomized, double-blind crossover study consisting of two, 5-d energy deficits (-30 ± 4% of total energy requirements), separated by 14-d. Following each energy deficit, mixed MPS and whole-body protein synthesis (PS), breakdown (PB), and net balance (NET) were determined at rest and post-resistance exercise (RE) using primed, constant L-[2H5]-phenylalanine and L-[2H2]-tyrosine infusions. Beverages providing standard (0.1 g/kg, 7.87 ± 0.87 g) or high (0.3 g/kg, 23.5 ± 2.54 g) EAA were consumed post-RE. Circulating EAA were measured. RESULTS Postabsorptive mixed MPS (%/h) at rest was not different (P = 0.67) between treatments. Independent of EAA, postprandial mixed MPS at rest (standard EAA, 0.055 ± 0.01; high EAA, 0.061 ± 0.02) and post-RE (standard EAA, 0.055 ± 0.01; high EAA, 0.065 ± 0.02) were greater than postabsorptive mixed MPS at rest (P = 0.02 and P = 0.01, respectively). Change in (Δ postabsorptive) whole-body (g/180 min) PS and PB was greater for high than standard EAA [mean treatment difference (95% CI), 3.4 (2.3, 4.4); P = 0.001 and -15.6 (-17.8, -13.5); P = 0.001, respectively]. NET was more positive for high than standard EAA [19.0 (17.3, 20.7); P = 0.001]. EAA concentrations were greater in high than standard EAA (P = 0.001). CONCLUSIONS These data demonstrate that high compared to standard EAA ingestion enhances whole-body protein status during underfeeding. However, the effects of consuming high and standard EAA on mixed MPS are the same during energy deficit. CLINICAL TRIAL REGISTRY NCT03372928, https://clinicaltrials.gov.
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37
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Pasiakos SM. Nutritional Requirements for Sustaining Health and Performance During Exposure to Extreme Environments. Annu Rev Nutr 2020; 40:221-245. [PMID: 32530730 DOI: 10.1146/annurev-nutr-011720-122637] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dietary guidelines are formulated to meet minimum nutrient requirements, which prevent deficiencies and maintain health, growth, development, and function. These guidelines can be inadequate and contribute to disrupted homeostasis, lean body mass loss, and deteriorated performance in individuals who are working long, arduous hours with limited access to food in environmentally challenging locations. Environmental extremes can elicit physiological adjustments that alone alter nutrition requirements by upregulating energy expenditure, altering substrate metabolism, and accelerating body water and muscle protein loss. The mechanisms by which the environment, including high-altitude, heat, and cold exposure, alters nutrition requirements have been studied extensively. This contemporary review discusses physiological adjustments to environmental extremes, particularly when those adjustments alter dietary requirements.
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Affiliation(s)
- Stefan M Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760, USA;
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38
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Øfsteng SJ, Garthe I, Jøsok Ø, Knox S, Helkala K, Knox B, Ellefsen S, Rønnestad BR. No effect of increasing protein intake during military exercise with severe energy deficit on body composition and performance. Scand J Med Sci Sports 2020; 30:865-877. [DOI: 10.1111/sms.13634] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 01/31/2020] [Accepted: 02/04/2020] [Indexed: 12/21/2022]
Affiliation(s)
| | - Ina Garthe
- Norwegian Olympic Sport Center Oslo Norway
| | - Øyvind Jøsok
- Inland Norway University of Applied Sciences Lillehammer Norway
- Norwegian Defence Cyber Academy Lillehammer Norway
| | - Silje Knox
- Norwegian Defence Cyber Academy Lillehammer Norway
| | | | - Ben Knox
- Norwegian Defence Cyber Academy Lillehammer Norway
| | - Stian Ellefsen
- Inland Norway University of Applied Sciences Lillehammer Norway
- Innlandet Hospital Trust Brumunddal Norway
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39
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Karl JP, Berryman CE, Harris MN, Lieberman HR, Gadde KM, Rood JC, Pasiakos SM. Effects of Testosterone Supplementation on Ghrelin and Appetite During and After Severe Energy Deficit in Healthy Men. J Endocr Soc 2020; 4:bvaa024. [PMID: 32258956 DOI: 10.1210/jendso/bvaa024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 02/26/2020] [Indexed: 12/17/2022] Open
Abstract
Background Severe energy deficits cause interrelated reductions in testosterone and fat free mass. Testosterone supplementation may mitigate those decrements, but could also reduce circulating concentrations of the orexigenic hormone ghrelin, thereby exacerbating energy deficit by suppressing appetite. Objective To determine whether testosterone supplementation during severe energy deficit influences fasting and postprandial ghrelin concentrations and appetite. Design and methods Secondary analysis of a randomized, double-blind trial that determined the effects of testosterone supplementation on body composition changes during and following severe energy deficit in nonobese, eugonadal men. Phase 1 (PRE-ED): 14-day run-in; phase 2: 28 days, 55% energy deficit with 200 mg testosterone enanthate weekly (TEST; n = 24) or placebo (PLA; n = 26); phase 3: free-living until body mass recovered (end-of-study; EOS). Fasting and postprandial acyl ghrelin and des-acyl ghrelin concentrations and appetite were secondary outcomes measured during the final week of each phase. Results Fasting acyl ghrelin concentrations, and postprandial acyl and des-acyl ghrelin concentrations increased in PLA during energy deficit then returned to PRE-ED values by EOS, but did not change in TEST (phase-by-group, P < 0.05). Correlations between changes in free testosterone and changes in fasting acyl ghrelin concentrations during energy deficit (ρ = -0.42, P = 0.003) and body mass recovery (ρ = -0.38; P = 0.01) were not mediated by changes in body mass or body composition. Transient increases in appetite during energy deficit were not affected by testosterone treatment. Conclusions Testosterone supplementation during short-term, severe energy deficit in healthy men prevents deficit-induced increases in circulating ghrelin without blunting concomitant increases in appetite. Clinical Trials Registration www.clinicaltrials.gov NCT02734238 (registered 12 April 2016).
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Affiliation(s)
- J Philip Karl
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Claire E Berryman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA.,Oak Ridge Institute for Science and Education, Belcamp, MD, USA.,Department of Nutrition, Food, and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - Melissa N Harris
- Louisiana State University's Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Harris R Lieberman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Kishore M Gadde
- Louisiana State University's Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Jennifer C Rood
- Louisiana State University's Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
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40
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Bartlett JD, Hatfield M, Parker BB, Roberts LA, Minahan C, Morton JP, Thornton HR. DXA-derived estimates of energy balance and its relationship with changes in body composition across a season in team sport athletes. Eur J Sport Sci 2019; 20:859-867. [PMID: 31526240 DOI: 10.1080/17461391.2019.1669718] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This study examined the relationship between dual-energy x-ray absorptiometry (DXA)-derived estimates of energy balance (EB) and changes in body composition across various seasonal phases in team sport athletes. Forty-five Australian rules footballers underwent six DXA scans across a 12-month period (off-season [OS, Week 0-13], early [PS1, Week 13-22] and late pre-season [PS2, Week 22-31] and early [IS1, Week 3-42] and late in-season [IS2, Week 42-51]). EB (kcal·day-1) was estimated from changes in fat free soft tissue mass (FFSTM) and fat mass (FM) between scans according to a validated formula. An EB threshold of ± 123 kcal·day-1 for >60 days demonstrated a very likely (>95% probability) change in FFSTM (>1.0 kg) and FM (>0.7 kg). There were small to almost perfect relationships between EB and changes in FM (r = 0.97, 95% CI, 0.96-0.98), FFSTM (r = -0.41, -0.92 to -0.52) and body mass (r = 0.27, 0.14-0.40). EB was lowest during PS1 compared to all other phases (range, -265 to -142 kcal·day-1), with no other changes at any time. Increases in FFSTM were higher during OS compared to PS2 (1.6 ± 0.4 kg), and higher during PS1 compared to PS2, IS1, and IS2 (range, 1.6-2.1 kg). There were no changes during in-season (-0.1-0.05 kg). FM decreased only in PS1 compared to all other seasonal phases (-1.8 to -1.0 kg). Assessments of body composition can be used as a tool to estimate EB, which practically can be used to indicate athlete's training and nutrition behaviours/practices.
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Affiliation(s)
- Jonathan D Bartlett
- Institute for Health and Sport, Victoria University, Melbourne, Australia.,Bond Institute of Health and Sport Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Australia.,Gold Coast Suns Football Club, Carrara, Australia
| | | | - Ben B Parker
- Gold Coast Suns Football Club, Carrara, Australia
| | - Llion A Roberts
- Griffith Sports Physiology and Performance, Griffith University, Gold Coast, Australia.,Sports Performance Innovation and Knowledge Excellence (SPIKE), Queensland Academy of Sport, Brisbane, Australia.,School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, Australia
| | - Clare Minahan
- Griffith Sports Physiology and Performance, Griffith University, Gold Coast, Australia
| | - James P Morton
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
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Effects of testosterone supplementation on body composition and lower-body muscle function during severe exercise- and diet-induced energy deficit: A proof-of-concept, single centre, randomised, double-blind, controlled trial. EBioMedicine 2019; 46:411-422. [PMID: 31358477 PMCID: PMC6711889 DOI: 10.1016/j.ebiom.2019.07.059] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 07/23/2019] [Accepted: 07/23/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Severe energy deficits during military operations, produced by significant increases in exercise and limited dietary intake, result in conditions that degrade lean body mass and lower-body muscle function, which may be mediated by concomitant reductions in circulating testosterone. METHODS We conducted a three-phase, proof-of-concept, single centre, randomised, double-blind, placebo-controlled trial (CinicalTrials.gov, NCT02734238) of non-obese men: 14-d run-in, free-living, eucaloric diet phase; 28-d live-in, 55% exercise- and diet-induced energy deficit phase with (200 mg testosterone enanthate per week, Testosterone, n = 24) or without (Placebo, n = 26) exogenous testosterone; and 14-d recovery, free-living, ad libitum diet phase. Body composition was the primary end point; secondary endpoints included lower-body muscle function and health-related biomarkers. FINDINGS Following energy deficit, lean body mass increased in Testosterone and remained stable in Placebo, such that lean body mass significantly differed between groups [mean difference between groups (95% CI), 2.5 kg (3.3, 1.6); P < .0001]. Fat mass decreased similarly in both treatment groups [0.2 (-0.4, 0.7), P = 1]. Change in lean body mass was associated with change in total testosterone (r = 0.71, P < .0001). Supplemental testosterone had no effect on lower-body muscle function or health-related biomarkers. INTERPRETATION Findings suggest that supplemental testosterone may increase lean body mass during short-term severe energy deficit in non-obese, young men, but it does not appear to attenuate lower-body functional decline. FUNDING Collaborative Research to Optimize Warfighter Nutrition projects I and II, Joint Program Committee-5, funded by the US Department of Defence.
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42
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Church DD, Gwin JA, Wolfe RR, Pasiakos SM, Ferrando AA. Mitigation of Muscle Loss in Stressed Physiology: Military Relevance. Nutrients 2019; 11:nu11081703. [PMID: 31344809 PMCID: PMC6724061 DOI: 10.3390/nu11081703] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 07/15/2019] [Accepted: 07/22/2019] [Indexed: 12/14/2022] Open
Abstract
Military personnel may be exposed to circumstances (e.g., large energy deficits, sleep deprivation, cognitive demands, and environmental extremes) of external stressors during training and combat operations (i.e., operational stressors) that combine to degrade muscle protein. The loss of muscle protein is further exacerbated by frequent periods of severe energy deficit. Exposure to these factors results in a hypogonadal state that may contribute to observed decrements in muscle mass. In this review, lessons learned from studying severe clinical stressed states and the interventions designed to mitigate the loss of muscle protein are discussed in the context of military operational stress. For example, restoration of the anabolic hormonal status (e.g., testosterone, insulin, and growth hormone) in stressed physiological states may be necessary to restore the anabolic influence derived from dietary protein on muscle. Based on our clinical experiences, restoration of the normal testosterone status during sustained periods of operational stress may be advantageous. We demonstrated that in severe burn patients, pharmacologic normalization of the anabolic hormonal status restores the anabolic stimulatory effect of nutrition on muscle by improving the protein synthetic efficiency and limiting amino acid loss from skeletal muscle. Furthermore, an optimal protein intake, and in particular essential amino acid delivery, may be an integral ingredient in a restored anabolic response during the stress state. Interventions which improve the muscle net protein balance may positively impact soldier performance in trying conditions.
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Affiliation(s)
- David D Church
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Jess A Gwin
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
- Oak Ridge Institute for Science and Education Supporting the Military Nutrition Division of the US Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
| | - Robert R Wolfe
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA
| | - Arny A Ferrando
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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43
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Carbone JW, Pasiakos SM. Dietary Protein and Muscle Mass: Translating Science to Application and Health Benefit. Nutrients 2019; 11:nu11051136. [PMID: 31121843 PMCID: PMC6566799 DOI: 10.3390/nu11051136] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/08/2019] [Accepted: 05/20/2019] [Indexed: 12/14/2022] Open
Abstract
Adequate consumption of dietary protein is critical for the maintenance of optimal health during normal growth and aging. The current Recommended Dietary Allowance (RDA) for protein is defined as the minimum amount required to prevent lean body mass loss, but is often misrepresented and misinterpreted as a recommended optimal intake. Over the past two decades, the potential muscle-related benefits achieved by consuming higher-protein diets have become increasingly clear. Despite greater awareness of how higher-protein diets might be advantageous for muscle mass, actual dietary patterns, particularly as they pertain to protein, have remained relatively unchanged in American adults. This lack of change may, in part, result from confusion over the purported detrimental effects of higher-protein diets. This manuscript will highlight common perceptions and benefits of dietary protein on muscle mass, address misperceptions related to higher-protein diets, and comment on the translation of academic advances to real-life application and health benefit. Given the vast research evidence supporting the positive effects of dietary protein intake on optimal health, we encourage critical evaluation of current protein intake recommendations and responsible representation and application of the RDA as a minimum protein requirement rather than one determined to optimally meet the needs of the population.
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Affiliation(s)
- John W Carbone
- School of Health Sciences, Eastern Michigan University, Ypsilanti, MI 48197, USA.
| | - Stefan M Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine (USARIEM), Natick, MA 01760, USA.
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Schalt A, Johannsen MM, Kim J, Chen R, Murphy CJ, Coker MS, Gunga HC, Coker RH, Steinach M. Negative Energy Balance Does Not Alter Fat-Free Mass During the Yukon Arctic Ultra-The Longest and the Coldest Ultramarathon. Front Physiol 2018; 9:1761. [PMID: 30662406 PMCID: PMC6327832 DOI: 10.3389/fphys.2018.01761] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 11/22/2018] [Indexed: 01/19/2023] Open
Abstract
Purpose: The objective of this study was to determine alterations in caloric balance, body composition, metabolites, and cytokines in athletes participating in the Yukon Arctic Ultra. Methods: Ten participants traveling on foot in the 2017 692-km event were recruited for the study. Measurements and samples were obtained at pre-event, 278 km (C1), 384 km (C2), and post-event. Body composition measurements were obtained using bioelectrical impedance analysis. Accelerometer devices were utilized to provide an estimation of caloric expenditure and dietary recalls provided assessments of caloric intake. Blood serum samples were collected, processed, and analyzed using enzyme-linked immunosorbent assays or nuclear magnetic resonance. Results were analyzed using linear mixed model, presented as means ± SD, and considered significant at p < 0.05. Results: Participants (8 males, 2 females; age: 37 ± 10 years; body mass index: 24.4 ± 2.5 kg/m2) were recruited. Four males and one female completed the entire event in 260 ± 19 h. Caloric intake/expenditure was 4,126 ± 1,115 kcal/day and 6,387 ± 781 kcal/day, respectively, indicating a caloric deficit of 2,261 ± 1,543 kcal/day. Total mass, body mass index, and fat mass were reduced at each time point of the event. Fat-free mass (FFM) was unchanged throughout the event. Follistatin was increased at C1 (1,715 ± 876 pg/ml) in comparison to baseline. Acetoacetate increased significantly at post-event (6.1 ± 1.5 mg/ml). Conclusions: Despite a pronounced caloric deficit and sustained activity under extreme cold conditions, FFM was preserved with an increase in serum follistatin and acetoacetate. Future studies should be directed at the role of nutrient strategies and/or training methods on the retention of FFM under these conditions.
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Affiliation(s)
- Adriane Schalt
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Michelle M Johannsen
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Jimin Kim
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Richard Chen
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Carl J Murphy
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Melynda S Coker
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Hanns-Christian Gunga
- Charité - Universitätsmedizin Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany
| | - Robert H Coker
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Mathias Steinach
- Charité - Universitätsmedizin Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany
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