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Brown MA, Howatson G, Quin E, Redding E, Stevenson EJ. Energy intake and energy expenditure of pre-professional female contemporary dancers. PLoS One 2017; 12:e0171998. [PMID: 28212449 PMCID: PMC5315282 DOI: 10.1371/journal.pone.0171998] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 01/30/2017] [Indexed: 01/29/2023] Open
Abstract
Many athletes in aesthetic and weight dependent sports are at risk of energy imbalance. However little is known about the exercise and eating behaviours of highly trained dance populations. This investigation sought to determine the energy intake and energy expenditure of pre-professional female contemporary dancers. Twenty-five female contemporary dance students completed the study. Over a 7-day period, including five week days (with scheduled dance training at a conservatoire) and two weekend days (with no scheduled dance training at the conservatoire), energy intake (self-reported weighed food diary and 24 h dietary recall) and expenditure (tri-axial accelerometry) were recorded. Mean daily energy intake and expenditure were different over the 7-day period (P = 0.014) equating to an energy deficit of -356 ± 668 kcal·day-1 (or -1.5 ± 2.8 MJ·day-1). Energy expenditure was not different when comparing week and weekend days (P = 0.297). However daily energy intake (P = 0.002), energy availability (P = 0.003), and energy balance (P = 0.004) were lower during the week compared to the weekend, where energy balance became positive. The percentage contribution of macronutrients to total energy intake also differed; with higher fat (P = 0.022) and alcohol (P = 0.020), and lower carbohydrate (P = 0.001) and a trend for lower protein (P = 0.051) at the weekend. Energy balance and appropriate macronutrient intake are essential for maintaining the demands of training, performance and recovery. Whilst aesthetics are important, female contemporary dancers may be at risk of the numerous health and performance impairments associated with negative energy balance, particularly during periods of scheduled training.
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Affiliation(s)
- Meghan A. Brown
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, United Kingdom
- School of Sport and Exercise, University of Gloucestershire, Gloucester, GL2 9HW, United Kingdom
| | - Glyn Howatson
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, United Kingdom
- Water Research Group, School of Biological Sciences, North West University, Potchefstroom, South Africa
- * E-mail:
| | - Edel Quin
- Faculty of Dance, Trinity Laban Conservatoire of Music and Dance, London, SE8 3DZ, United Kingdom
| | - Emma Redding
- Faculty of Dance, Trinity Laban Conservatoire of Music and Dance, London, SE8 3DZ, United Kingdom
| | - Emma J. Stevenson
- Institute of Cellular Medicine, Newcastle University, Newcastle, NE2 4HH, United Kingdom
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152
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Hulmi JJ, Isola V, Suonpää M, Järvinen NJ, Kokkonen M, Wennerström A, Nyman K, Perola M, Ahtiainen JP, Häkkinen K. The Effects of Intensive Weight Reduction on Body Composition and Serum Hormones in Female Fitness Competitors. Front Physiol 2017; 7:689. [PMID: 28119632 PMCID: PMC5222856 DOI: 10.3389/fphys.2016.00689] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 12/23/2016] [Indexed: 11/13/2022] Open
Abstract
Worries about the potential negative consequences of popular fat loss regimens for aesthetic purposes in normal weight females have been surfacing in the media. However, longitudinal studies investigating these kinds of diets are lacking. The purpose of the present study was to investigate the effects of a 4-month fat-loss diet in normal weight females competing in fitness-sport. In total 50 participants finished the study with 27 females (27.2 ± 4.1 years) dieting for a competition and 23 (27.7 ± 3.7 years) acting as weight-stable controls. The energy deficit of the diet group was achieved by reducing carbohydrate intake and increasing aerobic exercise while maintaining a high level of protein intake and resistance training in addition to moderate fat intake. The diet led to a ~12% decrease in body weight (P < 0.001) and a ~35-50% decrease in fat mass (DXA, bioimpedance, skinfolds, P < 0.001) whereas the control group maintained their body and fat mass (diet × group interaction P < 0.001). A small decrease in lean mass (bioimpedance and skinfolds) and in vastus lateralis muscle cross-sectional area (ultrasound) were observed in diet (P < 0.05), whereas other results were unaltered (DXA: lean mass, ultrasound: triceps brachii thickness). The hormonal system was altered during the diet with decreased serum concentrations of leptin, triiodothyronine (T3), testosterone (P < 0.001), and estradiol (P < 0.01) coinciding with an increased incidence of menstrual irregularities (P < 0.05). Body weight and all hormones except T3 and testosterone returned to baseline during a 3-4 month recovery period including increased energy intake and decreased levels aerobic exercise. This study shows for the first time that most of the hormonal changes after a 35-50% decrease in body fat in previously normal-weight females can recover within 3-4 months of increased energy intake.
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Affiliation(s)
- Juha J Hulmi
- Department of Biology of Physical Activity, Neuromuscular Research Center, University of JyväskyläJyväskylä, Finland; Department of Physiology, Faculty of Medicine, University of HelsinkiHelsinki, Finland
| | - Ville Isola
- Department of Biology of Physical Activity, Neuromuscular Research Center, University of Jyväskylä Jyväskylä, Finland
| | - Marianna Suonpää
- Department of Health Sciences, University of Jyväskylä Jyväskylä, Finland
| | - Neea J Järvinen
- Department of Biology of Physical Activity, Neuromuscular Research Center, University of Jyväskylä Jyväskylä, Finland
| | - Marja Kokkonen
- Department of Physical Education, University of Jyväskylä Jyväskylä, Finland
| | - Annika Wennerström
- Genomics and Biomarkers Unit, Department of Health, National Institute for Health and WelfareHelsinki, Finland; Institute for Molecular Medicine Finland and Diabetes and Obesity Research Program, University of HelsinkiHelsinki, Finland
| | - Kai Nyman
- Central Hospital of Central Finland Jyväskylä, Finland
| | - Markus Perola
- Genomics and Biomarkers Unit, Department of Health, National Institute for Health and WelfareHelsinki, Finland; Institute for Molecular Medicine Finland and Diabetes and Obesity Research Program, University of HelsinkiHelsinki, Finland; The Estonian Genome Center of the University of TartuTartu, Estonia
| | - Juha P Ahtiainen
- Department of Biology of Physical Activity, Neuromuscular Research Center, University of Jyväskylä Jyväskylä, Finland
| | - Keijo Häkkinen
- Department of Biology of Physical Activity, Neuromuscular Research Center, University of Jyväskylä Jyväskylä, Finland
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153
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Smiles WJ, Hawley JA, Camera DM. Effects of skeletal muscle energy availability on protein turnover responses to exercise. ACTA ACUST UNITED AC 2016; 219:214-25. [PMID: 26792333 DOI: 10.1242/jeb.125104] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Skeletal muscle adaptation to exercise training is a consequence of repeated contraction-induced increases in gene expression that lead to the accumulation of functional proteins whose role is to blunt the homeostatic perturbations generated by escalations in energetic demand and substrate turnover. The development of a specific 'exercise phenotype' is the result of new, augmented steady-state mRNA and protein levels that stem from the training stimulus (i.e. endurance or resistance based). Maintaining appropriate skeletal muscle integrity to meet the demands of training (i.e. increases in myofibrillar and/or mitochondrial protein) is regulated by cyclic phases of synthesis and breakdown, the rate and turnover largely determined by the protein's half-life. Cross-talk among several intracellular systems regulating protein synthesis, breakdown and folding is required to ensure protein equilibrium is maintained. These pathways include both proteasomal and lysosomal degradation systems (ubiquitin-mediated and autophagy, respectively) and the protein translational and folding machinery. The activities of these cellular pathways are bioenergetically expensive and are modified by intracellular energy availability (i.e. macronutrient intake) and the 'training impulse' (i.e. summation of the volume, intensity and frequency). As such, exercise-nutrient interactions can modulate signal transduction cascades that converge on these protein regulatory systems, especially in the early post-exercise recovery period. This review focuses on the regulation of muscle protein synthetic response-adaptation processes to divergent exercise stimuli and how intracellular energy availability interacts with contractile activity to impact on muscle remodelling.
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Affiliation(s)
- William J Smiles
- Centre for Exercise and Nutrition, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3065, Australia
| | - John A Hawley
- Centre for Exercise and Nutrition, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3065, Australia Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool L3 3AF, UK
| | - Donny M Camera
- Centre for Exercise and Nutrition, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3065, Australia
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154
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Impey SG, Hammond KM, Shepherd SO, Sharples AP, Stewart C, Limb M, Smith K, Philp A, Jeromson S, Hamilton DL, Close GL, Morton JP. Fuel for the work required: a practical approach to amalgamating train-low paradigms for endurance athletes. Physiol Rep 2016; 4:4/10/e12803. [PMID: 27225627 PMCID: PMC4886170 DOI: 10.14814/phy2.12803] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 04/29/2016] [Indexed: 01/09/2023] Open
Abstract
Using an amalgamation of previously studied "train-low" paradigms, we tested the effects of reduced carbohydrate (CHO) but high leucine availability on cell-signaling responses associated with exercise-induced regulation of mitochondrial biogenesis and muscle protein synthesis (MPS). In a repeated-measures crossover design, 11 males completed an exhaustive cycling protocol with high CHO availability before, during, and after exercise (HIGH) or alternatively, low CHO but high protein (leucine enriched) availability (LOW + LEU). Muscle glycogen was different (P < 0.05) pre-exercise (HIGH: 583 ± 158, LOW + LEU: 271 ± 85 mmol kg(-1) dw) but decreased (P < 0.05) to comparable levels at exhaustion (≈100 mmol kg(-1) dw). Despite differences (P < 0.05) in exercise capacity (HIGH: 158 ± 29, LOW + LEU: 100 ± 17 min), exercise induced (P < 0.05) comparable AMPKα2 (3-4-fold) activity, PGC-1α (13-fold), p53 (2-fold), Tfam (1.5-fold), SIRT1 (1.5-fold), Atrogin 1 (2-fold), and MuRF1 (5-fold) gene expression at 3 h post-exercise. Exhaustive exercise suppressed p70S6K activity to comparable levels immediately post-exercise (≈20 fmol min(-1) mg(-1)). Despite elevated leucine availability post-exercise, p70S6K activity remained suppressed (P < 0.05) 3 h post-exercise in LOW + LEU (28 ± 14 fmol min(-1) mg(-1)), whereas muscle glycogen resynthesis (40 mmol kg(-1) dw h(-1)) was associated with elevated (P < 0.05) p70S6K activity in HIGH (53 ± 30 fmol min(-1) mg(-1)). We conclude: (1) CHO restriction before and during exercise induces "work-efficient" mitochondrial-related cell signaling but; (2) post-exercise CHO and energy restriction maintains p70S6K activity at basal levels despite feeding leucine-enriched protein. Our data support the practical concept of "fuelling for the work required" as a potential strategy for which to amalgamate train-low paradigms into periodized training programs.
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Affiliation(s)
- Samuel G Impey
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Kelly M Hammond
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Sam O Shepherd
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Adam P Sharples
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Claire Stewart
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Marie Limb
- MRC-ARUK Centre for Musculoskeletal Aging, Research Division of Medical Sciences and Graduate Entry Medicine, School of Medicine Faculty of Medicine and Health Sciences, University of Nottingham Royal Derby Hospital Centre, Derby, UK
| | - Kenneth Smith
- MRC-ARUK Centre for Musculoskeletal Aging, Research Division of Medical Sciences and Graduate Entry Medicine, School of Medicine Faculty of Medicine and Health Sciences, University of Nottingham Royal Derby Hospital Centre, Derby, UK
| | - Andrew Philp
- MRC-ARUK Centre for Musculoskeletal Aging Research, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Stewart Jeromson
- Health and Exercise Sciences Research Group, University of Stirling, Stirling, UK
| | - D Lee Hamilton
- Health and Exercise Sciences Research Group, University of Stirling, Stirling, UK
| | - Graeme L Close
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - James P Morton
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
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155
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Margolis LM, Rivas DA, Berrone M, Ezzyat Y, Young AJ, McClung JP, Fielding RA, Pasiakos SM. Prolonged Calorie Restriction Downregulates Skeletal Muscle mTORC1 Signaling Independent of Dietary Protein Intake and Associated microRNA Expression. Front Physiol 2016; 7:445. [PMID: 27761114 PMCID: PMC5050214 DOI: 10.3389/fphys.2016.00445] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 09/20/2016] [Indexed: 01/18/2023] Open
Abstract
Short-term (5-10 days) calorie restriction (CR) downregulates muscle protein synthesis, with consumption of a high protein-based diet attenuating this decline. Benefit of increase protein intake is believed to be due to maintenance of amino acid-mediated anabolic signaling through the mechanistic target of rapamycin complex 1 (mTORC1), however, there is limited evidence to support this contention. The purpose of this investigation was to determine the effects of prolonged CR and high protein diets on skeletal muscle mTORC1 signaling and expression of associated microRNA (miR). Twelve-week old male Sprague Dawley rats consumed ad libitum (AL) or calorie restricted (CR; 40%) adequate (10%, AIN-93M) or high (32%) protein milk-based diets for 16 weeks. Body composition was determined using dual energy X-ray absorptiometry and muscle protein content was calculated from muscle homogenate protein concentrations expressed relative to fat-free mass to estimate protein content. Western blot and RT-qPCR were used to determine mTORC1 signaling and mRNA and miR expression in fasted mixed gastrocnemius. Independent of dietary protein intake, muscle protein content was 38% lower (P < 0.05) in CR compared to AL. Phosphorylation and total Akt, mTOR, rpS6, and p70S6K were lower (P < 0.05) in CR vs. AL, and total rpS6 was associated with muscle protein content (r = 0.64, r2 = 0.36). Skeletal muscle miR expression was not altered by either energy or protein intake. This study provides evidence that chronic CR attenuates muscle protein content by downregulating mTORC1 signaling. This response is independent of skeletal muscle miR and dietary protein.
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Affiliation(s)
- Lee M Margolis
- Nutrition, Exercise, Physiology, and Sarcopenia Laboratory, U.S. Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts UniversityBoston, MA, USA; Military Nutrition Division, US Army Research Institute of Environmental MedicineNatick, MA, USA
| | - Donato A Rivas
- Nutrition, Exercise, Physiology, and Sarcopenia Laboratory, U.S. Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts University Boston, MA, USA
| | - Maria Berrone
- Nutrition, Exercise, Physiology, and Sarcopenia Laboratory, U.S. Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts University Boston, MA, USA
| | - Yassine Ezzyat
- Nutrition, Exercise, Physiology, and Sarcopenia Laboratory, U.S. Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts University Boston, MA, USA
| | - Andrew J Young
- Military Nutrition Division, US Army Research Institute of Environmental Medicine Natick, MA, USA
| | - James P McClung
- Military Nutrition Division, US Army Research Institute of Environmental Medicine Natick, MA, USA
| | - Roger A Fielding
- Nutrition, Exercise, Physiology, and Sarcopenia Laboratory, U.S. Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts University Boston, MA, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine Natick, MA, USA
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156
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Abstract
Weight management for athletes and active individuals is unique because of their high daily energy expenditure; thus, the emphasis is usually placed on changing the diet side of the energy balance equation. When dieting for weight loss, active individuals also want to preserve lean tissue, which means that energy restriction cannot be too severe or lean tissue is lost. First, this brief review addresses the issues of weight management in athletes and active individuals and factors to consider when determining a weight-loss goal. Second, the concept of dynamic energy balance is reviewed, including two mathematical models developed to improve weight-loss predictions based on changes in diet and exercise. These models are now available on the Internet. Finally, dietary strategies for weight loss/maintenance that can be successfully used with active individuals are given. Emphasis is placed on teaching the benefits of consuming a low-ED diet (e.g., high-fiber, high-water, low-fat foods), which allows for the consumption of a greater volume of food to increase satiety while reducing energy intake. Health professionals and sport dietitians need to understand dynamic energy balance and be prepared with effective and evidence-based dietary approaches to help athletes and active individuals achieve their body-weight goals.
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157
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MARGOLIS LEEM, MURPHY NANCYE, MARTINI SVEIN, GUNDERSEN YNGVAR, CASTELLANI JOHNW, KARL JPHILIP, CARRIGAN CHRISTOPHERT, TEIEN HILDEKRISTIN, MADSLIEN ELISABETHHENIE, MONTAIN SCOTTJ, PASIAKOS STEFANM. Effects of Supplemental Energy on Protein Balance during 4-d Arctic Military Training. Med Sci Sports Exerc 2016; 48:1604-12. [DOI: 10.1249/mss.0000000000000944] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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158
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Karl JP, Smith TJ, Wilson MA, Bukhari AS, Pasiakos SM, McClung HL, McClung JP, Lieberman HR. Altered metabolic homeostasis is associated with appetite regulation during and following 48-h of severe energy deprivation in adults. Metabolism 2016; 65:416-27. [PMID: 26975533 DOI: 10.1016/j.metabol.2015.11.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 09/29/2015] [Accepted: 11/04/2015] [Indexed: 12/19/2022]
Abstract
BACKGROUND Military personnel frequently endure intermittent periods of severe energy deficit which can compromise health and performance. Physiologic factors contributing to underconsumption, and the subsequent drive to overeat, are not fully characterized. This study aimed to identify associations between appetite, metabolic homeostasis and endocrine responses during and following severe, short-term energy deprivation. METHODS Twenty-three young adults (17M/6F, 21±3years, BMI 25±3kg/m(2)) participated in a randomized, controlled, crossover trial. During separate 48-h periods, participants increased habitual energy expenditure by 1647±345kcal/d (mean±SD) through prescribed exercise at 40-65% VO2peak, and consumed provided isovolumetric diets designed to maintain energy balance at the elevated energy expenditure (EB; 36±93kcal/d energy deficit) or to produce a severe energy deficit (ED; 3681±716kcal/d energy deficit). Appetite, markers of metabolic homeostasis and endocrine mediators of appetite and substrate availability were periodically measured. Ad libitum energy intake was measured over 36h following both experimental periods. RESULTS Appetite increased during ED and was greater than during EB despite maintenance of diet volume (P=0.004). Ad libitum energy intake was 907kcal/36h [95% CI: 321, 1493kcal/36h, P=0.004] higher following ED compared to following EB. Serum beta-hydroxybutyrate, free fatty acids, branched-chain amino acids, dehydroepiandrosterone-sulfate (DHEA-S) and cortisol concentrations were higher (P<0.001 for all), whereas whole-body protein balance was more negative (P<0.001), and serum glucose, insulin, and leptin concentrations were lower (P<0.001 for all) during ED relative to during EB. Cortisol concentrations, but not any other hormone or metabolic substrate, were inversely associated with satiety during EB (R(2)=0.23, P=0.04). In contrast, serum glucose and DHEA-S concentrations were inversely associated with satiety during ED (R(2)=0.68, P<0.001). No associations between physiologic variables measured during EB and ad libitum energy intake following EB were observed. However, serum leptin and net protein balance measured during ED were inversely associated with ad libitum energy intake following ED (R(2)=0.48, P=0.01). CONCLUSION These findings suggest that changes in metabolic homeostasis during energy deprivation modulate appetite independent of reductions in diet volume. Following energy deprivation, physiologic signals of adipose and lean tissue loss may drive restoration of energy balance. CLINICAL TRIALS REGISTRATION www.clinicaltrials.gov #NCT01603550.
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Affiliation(s)
- J Philip Karl
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg 42, Natick, MA 01760, USA.
| | - Tracey J Smith
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg 42, Natick, MA 01760, USA
| | - Marques A Wilson
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg 42, Natick, MA 01760, USA
| | - Asma S Bukhari
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg 42, Natick, MA 01760, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg 42, Natick, MA 01760, USA
| | - Holly L McClung
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg 42, Natick, MA 01760, USA
| | - James P McClung
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg 42, Natick, MA 01760, USA
| | - Harris R Lieberman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, 10 General Greene Ave, Bldg 42, Natick, MA 01760, USA
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159
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Schoenfeld BJ, Aragon AA, Moon J, Krieger JW, Tiryaki-Sonmez G. Comparison of amplitude-mode ultrasound versus air displacement plethysmography for assessing body composition changes following participation in a structured weight-loss programme in women. Clin Physiol Funct Imaging 2016; 37:663-668. [DOI: 10.1111/cpf.12355] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 01/22/2016] [Indexed: 11/30/2022]
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160
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Longland TM, Oikawa SY, Mitchell CJ, Devries MC, Phillips SM. Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial. Am J Clin Nutr 2016; 103:738-46. [PMID: 26817506 DOI: 10.3945/ajcn.115.119339] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 12/16/2015] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND A dietary protein intake higher than the Recommended Dietary Allowance during an energy deficit helps to preserve lean body mass (LBM), particularly when combined with exercise. OBJECTIVE The purpose of this study was to conduct a proof-of-principle trial to test whether manipulation of dietary protein intake during a marked energy deficit in addition to intense exercise training would affect changes in body composition. DESIGN We used a single-blind, randomized, parallel-group prospective trial. During a 4-wk period, we provided hypoenergetic (~40% reduction compared with requirements) diets providing 33 ± 1 kcal/kg LBM to young men who were randomly assigned (n = 20/group) to consume either a lower-protein (1.2 g · kg(-1) · d(-1)) control diet (CON) or a higher-protein (2.4 g · kg(-1) · d(-1)) diet (PRO). All subjects performed resistance exercise training combined with high-intensity interval training for 6 d/wk. A 4-compartment model assessment of body composition was made pre- and postintervention. RESULTS As a result of the intervention, LBM increased (P < 0.05) in the PRO group (1.2 ± 1.0 kg) and to a greater extent (P < 0.05) compared with the CON group (0.1 ± 1.0 kg). The PRO group had a greater loss of fat mass than did the CON group (PRO: -4.8 ± 1.6 kg; CON: -3.5 ± 1.4kg; P < 0.05). All measures of exercise performance improved similarly in the PRO and CON groups as a result of the intervention with no effect of protein supplementation. Changes in serum cortisol during the intervention were associated with changes in body fat (r = 0.39, P = 0.01) and LBM (r = -0.34, P = 0.03). CONCLUSIONS Our results showed that, during a marked energy deficit, consumption of a diet containing 2.4 g protein · kg(-1) · d(-1) was more effective than consumption of a diet containing 1.2 g protein · kg(-1) · d(-1) in promoting increases in LBM and losses of fat mass when combined with a high volume of resistance and anaerobic exercise. Changes in serum cortisol were associated with changes in body fat and LBM, but did not explain much variance in either measure. This trial was registered at clinicaltrials.gov as NCT01776359.
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Affiliation(s)
- Thomas M Longland
- Department of Kinesiology, Exercise Metabolism Research Group, McMaster University, Hamilton, Canada
| | - Sara Y Oikawa
- Department of Kinesiology, Exercise Metabolism Research Group, McMaster University, Hamilton, Canada
| | - Cameron J Mitchell
- Department of Kinesiology, Exercise Metabolism Research Group, McMaster University, Hamilton, Canada
| | - Michaela C Devries
- Department of Kinesiology, Exercise Metabolism Research Group, McMaster University, Hamilton, Canada
| | - Stuart M Phillips
- Department of Kinesiology, Exercise Metabolism Research Group, McMaster University, Hamilton, Canada
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161
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Wang S, Yang L, Lu J, Mu Y. High-protein breakfast promotes weight loss by suppressing subsequent food intake and regulating appetite hormones in obese Chinese adolescents. Horm Res Paediatr 2015; 83:19-25. [PMID: 24923232 DOI: 10.1159/000362168] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 03/04/2014] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE A high-protein diet may decrease food intake through regulating satiety and appetite hormones and can be an effective strategy for weight loss. Few studies exist on obese Chinese adolescents. METHODS AND MATERIALS 156 obese Chinese adolescents were enrolled and randomly assigned to one of two isoenergetic breakfasts, either with egg or steamed bread. Subsequent lunchtime food intake was recorded 4 h later. Appetite was assessed with a visual analog scale. Anorexigenic hormones peptide YY (PYY), glucagon-like peptide-1 (GLP-1) and orexigenic hormone ghrelin were determined with radioimmunoassay at 0, 30, and 180 min. Body weight was recorded. The tests were repeated 3 months later. Analysis was performed between two tests and then two groups. Pearson's correlation was used for association analysis. RESULTS Subsequent lunchtime food intake and body weight were decreased while satiety was increased in subjects on an egg breakfast, which is associated with an increase of serum PYY and GLP-1 (p < 0.001, respectively). There were strong correlations between weight loss, appetite, subsequent food intake and changes of appetite hormones. CONCLUSION A high-protein breakfast promotes weight loss in obese Chinese adolescents, possibly through its regulation of satiety, subsequent food intake and appetite hormones.
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Affiliation(s)
- Shaoyun Wang
- Department of Endocrinology, Chinese PLA General Hospital, Chinese PLA Medical College, Beijing, PR China
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162
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Hackney KJ, Scott JM, Hanson AM, English KL, Downs ME, Ploutz-Snyder LL. The Astronaut-Athlete. J Strength Cond Res 2015; 29:3531-45. [DOI: 10.1519/jsc.0000000000001191] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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163
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Backx EMP, Tieland M, Borgonjen-van den Berg KJ, Claessen PR, van Loon LJC, de Groot LCPGM. Protein intake and lean body mass preservation during energy intake restriction in overweight older adults. Int J Obes (Lond) 2015; 40:299-304. [PMID: 26471344 DOI: 10.1038/ijo.2015.182] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 08/13/2015] [Accepted: 08/23/2015] [Indexed: 12/15/2022]
Abstract
BACKGROUND Dietary-induced weight loss is generally accompanied by a decline in skeletal muscle mass. The loss of muscle mass leads to a decline in muscle strength and impairs physical performance. A high dietary protein intake has been suggested to allow muscle mass preservation during energy intake restriction. OBJECTIVE To investigate the impact of increasing dietary protein intake on lean body mass, strength and physical performance during 12 weeks of energy intake restriction in overweight older adults. DESIGN Sixty-one overweight and obese men and women (63±5 years) were randomly assigned to either a high protein diet (HP; 1.7 g kg(-1) per day; n=31) or normal protein diet (NP; 0.9 g kg(-1) per day; n=30) during a 12-week 25% energy intake restriction. During this controlled dietary intervention, 90% of the diet was provided by the university. At baseline and after the intervention, body weight, lean body mass (dual-energy X-ray absorptiometry), leg strength (1-repetition maximum), physical performance (Short Physical Performance Battery, 400 m) and habitual physical activity (actigraph) were assessed. RESULTS Body weight declined in both groups with no differences between the HP and NP groups (-8.9±2.9 versus -9.1±3.4 kg, respectively; P=0.584). Lean body mass declined by 1.8±2.2 and 2.1±1.4 kg, respectively, with no significant differences between groups (P=0.213). Leg strength had decreased during the intervention by 8.8±14.0 and 8.9±12.8 kg, with no differences between groups (P=0.689). Physical performance as measured by 400 m walking speed improved in both groups, with no differences between groups (P=0.219). CONCLUSIONS Increasing protein intake above habitual intake levels (0.9 g kg(-1) per day) does not preserve lean body mass, strength or physical performance during prolonged energy intake restriction in overweight older adults.
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Affiliation(s)
- E M P Backx
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.,Top Institute Food and Nutrition, Wageningen, The Netherlands
| | - M Tieland
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.,Top Institute Food and Nutrition, Wageningen, The Netherlands
| | | | - P R Claessen
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - L J C van Loon
- Top Institute Food and Nutrition, Wageningen, The Netherlands.,NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - L C P G M de Groot
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.,Top Institute Food and Nutrition, Wageningen, The Netherlands
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164
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Pasiakos SM, McClung HL, Margolis LM, Murphy NE, Lin GG, Hydren JR, Young AJ. Human Muscle Protein Synthetic Responses during Weight-Bearing and Non-Weight-Bearing Exercise: A Comparative Study of Exercise Modes and Recovery Nutrition. PLoS One 2015; 10:e0140863. [PMID: 26474292 PMCID: PMC4608805 DOI: 10.1371/journal.pone.0140863] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 10/01/2015] [Indexed: 12/05/2022] Open
Abstract
Effects of conventional endurance (CE) exercise and essential amino acid (EAA) supplementation on protein turnover are well described. Protein turnover responses to weighted endurance exercise (i.e., load carriage, LC) and EAA may differ from CE, because the mechanical forces and contractile properties of LC and CE likely differ. This study examined muscle protein synthesis (MPS) and whole-body protein turnover in response to LC and CE, with and without EAA supplementation, using stable isotope amino acid tracer infusions. Forty adults (mean ± SD, 22 ± 4 y, 80 ± 10 kg, VO2peak 4.0 ± 0.5 L∙min-1) were randomly assigned to perform 90 min, absolute intensity-matched (2.2 ± 0.1 VO2 L∙m-1) LC (performed on a treadmill wearing a vest equal to 30% of individual body mass, mean ± SD load carried 24 ± 3 kg) or CE (cycle ergometry performed at the same absolute VO2 as LC) exercise, during which EAA (10 g EAA, 3.6 g leucine) or control (CON, non-nutritive) drinks were consumed. Mixed-muscle and myofibrillar MPS were higher during exercise for LC than CE (mode main effect, P < 0.05), independent of dietary treatment. EAA enhanced mixed-muscle and sarcoplasmic MPS during exercise, regardless of mode (drink main effect, P < 0.05). Mixed-muscle and sarcoplasmic MPS were higher in recovery for LC than CE (mode main effect, P < 0.05). No other differences or interactions (mode x drink) were observed. However, EAA attenuated whole-body protein breakdown, increased amino acid oxidation, and enhanced net protein balance in recovery compared to CON, regardless of exercise mode (P < 0.05). These data show that, although whole-body protein turnover responses to absolute VO2-matched LC and CE are the same, LC elicited a greater muscle protein synthetic response than CE.
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Affiliation(s)
- Stefan M. Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America
- * E-mail:
| | - Holly L. McClung
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Lee M. Margolis
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Nancy E. Murphy
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Gregory G. Lin
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Jay R. Hydren
- Military Performance Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America
| | - Andrew J. Young
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America
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165
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Glynn EL, Piner LW, Huffman KM, Slentz CA, Elliot-Penry L, AbouAssi H, White PJ, Bain JR, Muehlbauer MJ, Ilkayeva OR, Stevens RD, Porter Starr KN, Bales CW, Volpi E, Brosnan MJ, Trimmer JK, Rolph TP, Newgard CB, Kraus WE. Impact of combined resistance and aerobic exercise training on branched-chain amino acid turnover, glycine metabolism and insulin sensitivity in overweight humans. Diabetologia 2015; 58:2324-35. [PMID: 26254576 PMCID: PMC4793723 DOI: 10.1007/s00125-015-3705-6] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 06/24/2015] [Indexed: 12/11/2022]
Abstract
AIMS/HYPOTHESES Obesity is associated with decreased insulin sensitivity (IS) and elevated plasma branched-chain amino acids (BCAAs). The purpose of this study was to investigate the relationship between BCAA metabolism and IS in overweight (OW) individuals during exercise intervention. METHODS Whole-body leucine turnover, IS by hyperinsulinaemic-euglycaemic clamp, and circulating and skeletal muscle amino acids, branched-chain α-keto acids and acylcarnitines were measured in ten healthy controls (Control) and nine OW, untrained, insulin-resistant individuals (OW-Untrained). OW-Untrained then underwent a 6 month aerobic and resistance exercise programme and repeated testing (OW-Trained). RESULTS IS was higher in Control vs OW-Untrained and increased significantly following exercise. IS was lower in OW-Trained vs Control expressed relative to body mass, but was not different from Control when normalised to fat-free mass (FFM). Plasma BCAAs and leucine turnover (relative to FFM) were higher in OW-Untrained vs Control, but did not change on average with exercise. Despite this, within individuals, the decrease in molar sum of circulating BCAAs was the best metabolic predictor of improvement in IS. Circulating glycine levels were higher in Control and OW-Trained vs OW-Untrained, and urinary metabolic profiling suggests that exercise induces more efficient elimination of excess acyl groups derived from BCAA and aromatic amino acid (AA) metabolism via formation of urinary glycine adducts. CONCLUSIONS/INTERPRETATION A mechanism involving more efficient elimination of excess acyl groups derived from BCAA and aromatic AA metabolism via glycine conjugation in the liver, rather than increased BCAA disposal through oxidation and turnover, may mediate interactions between exercise, BCAA metabolism and IS. TRIAL REGISTRATION Clinicaltrials.gov NCT01786941.
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Affiliation(s)
- Erin L Glynn
- Sarah W. Stedman Nutrition & Metabolism Center, Duke University Medical Center, Durham, NC, USA
- Duke Molecular Physiology Institute, Duke University Medical Center, 300 North Duke Street, Durham, NC, 27701, USA
| | - Lucy W Piner
- Duke Molecular Physiology Institute, Duke University Medical Center, 300 North Duke Street, Durham, NC, 27701, USA
| | - Kim M Huffman
- Duke Molecular Physiology Institute, Duke University Medical Center, 300 North Duke Street, Durham, NC, 27701, USA
| | - Cris A Slentz
- Duke Molecular Physiology Institute, Duke University Medical Center, 300 North Duke Street, Durham, NC, 27701, USA
- Department of Medicine, Duke University Medical Center, Durham, NC, USA
- Department of Cardiology, Duke University Medical Center, Durham, NC, USA
| | - Lorraine Elliot-Penry
- Duke Molecular Physiology Institute, Duke University Medical Center, 300 North Duke Street, Durham, NC, 27701, USA
| | - Hiba AbouAssi
- Department of Medicine, Duke University Medical Center, Durham, NC, USA
- Division of Endocrinology, Duke University Medical Center, Durham, NC, USA
| | - Phillip J White
- Sarah W. Stedman Nutrition & Metabolism Center, Duke University Medical Center, Durham, NC, USA
- Duke Molecular Physiology Institute, Duke University Medical Center, 300 North Duke Street, Durham, NC, 27701, USA
| | - James R Bain
- Sarah W. Stedman Nutrition & Metabolism Center, Duke University Medical Center, Durham, NC, USA
- Duke Molecular Physiology Institute, Duke University Medical Center, 300 North Duke Street, Durham, NC, 27701, USA
- Department of Medicine, Duke University Medical Center, Durham, NC, USA
- Division of Endocrinology, Duke University Medical Center, Durham, NC, USA
| | - Michael J Muehlbauer
- Sarah W. Stedman Nutrition & Metabolism Center, Duke University Medical Center, Durham, NC, USA
- Duke Molecular Physiology Institute, Duke University Medical Center, 300 North Duke Street, Durham, NC, 27701, USA
| | - Olga R Ilkayeva
- Sarah W. Stedman Nutrition & Metabolism Center, Duke University Medical Center, Durham, NC, USA
- Duke Molecular Physiology Institute, Duke University Medical Center, 300 North Duke Street, Durham, NC, 27701, USA
| | - Robert D Stevens
- Sarah W. Stedman Nutrition & Metabolism Center, Duke University Medical Center, Durham, NC, USA
- Duke Molecular Physiology Institute, Duke University Medical Center, 300 North Duke Street, Durham, NC, 27701, USA
- Department of Medicine, Duke University Medical Center, Durham, NC, USA
- Division of Endocrinology, Duke University Medical Center, Durham, NC, USA
| | | | - Connie W Bales
- Department of Medicine, Duke University Medical Center, Durham, NC, USA
- Division of Geriatrics, Duke University Medical Center, Durham, NC, USA
- GRECC, Durham VA Medical Center, Durham, NC, USA
| | - Elena Volpi
- Sealy Center on Aging, University of Texas Medical Branch, Galveston, TX, USA
| | - M Julia Brosnan
- The CV and Metabolic Diseases Research Unit, Pfizer, Cambridge, MA, USA
| | - Jeff K Trimmer
- The CV and Metabolic Diseases Research Unit, Pfizer, Cambridge, MA, USA
| | - Timothy P Rolph
- The CV and Metabolic Diseases Research Unit, Pfizer, Cambridge, MA, USA
| | - Christopher B Newgard
- Sarah W. Stedman Nutrition & Metabolism Center, Duke University Medical Center, Durham, NC, USA.
- Duke Molecular Physiology Institute, Duke University Medical Center, 300 North Duke Street, Durham, NC, 27701, USA.
- Department of Medicine, Duke University Medical Center, Durham, NC, USA.
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, USA.
- Division of Endocrinology, Duke University Medical Center, Durham, NC, USA.
| | - William E Kraus
- Duke Molecular Physiology Institute, Duke University Medical Center, 300 North Duke Street, Durham, NC, 27701, USA.
- Department of Medicine, Duke University Medical Center, Durham, NC, USA.
- Department of Cardiology, Duke University Medical Center, Durham, NC, USA.
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166
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Shou Q, Chen F, Cai Y, Zhang S, Tu J, Zhang L, Wang D, Wang J, Chen M, Fu H. Inhibition of Diethylnitrosamine-Induced Hepatocarcinogenesis in Mice by a High Dietary Protein Intake. Nutr Cancer 2015; 67:1151-8. [PMID: 26359675 DOI: 10.1080/01635581.2015.1073761] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Epidemiological and experimental evidence supports the key role of diet in the development of many types of cancer. Recent studies have suggested that dietary modifications may be beneficial for individuals at high risk for hepatocellular carcinoma (HCC). In this study, we investigated the effect of a high-protein (HP; 20% casein) dietondiethylnitrosamine (DEN)-induced hepatocarcinogenesis. Mice were given free access to water with 30 μg/ml DEN and fed a normal or HP diet for 22 wk. The results showed mice consuming HP diets had reduced mortality rates and body weights and lower hepatic enzyme activity compared to DEN-treated mice on a normal diet. HP consumption also promoted collagen accumulation in the liver, and reduced numbers of proliferating hepatocytes and infiltrating inflammatory cells, as well as decreased expression of inflammatory factor interleukin-1β, and nuclear factor κB activation. These data indicate that HP diets can inhibit DEN-induced hepatocarcinogenesis via suppression of the inflammatory response and provide a new evidence for the dietary management of clinical patients with hepatocellular carcinoma.
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Affiliation(s)
- Qiyang Shou
- a Experimental Animal Research Center, Zhejiang Chinese Medical University , Hangzhou , China
| | - Fangming Chen
- a Experimental Animal Research Center, Zhejiang Chinese Medical University , Hangzhou , China
| | - Yueqin Cai
- a Experimental Animal Research Center, Zhejiang Chinese Medical University , Hangzhou , China
| | - Shanxin Zhang
- b Department of Orthopaedic Surgery , The First Affiliated Hospital of Zhejiang Chinese Medical University , Hangzhou , China
| | - Jue Tu
- a Experimental Animal Research Center, Zhejiang Chinese Medical University , Hangzhou , China
| | - Lizong Zhang
- a Experimental Animal Research Center, Zhejiang Chinese Medical University , Hangzhou , China
| | - Dejun Wang
- a Experimental Animal Research Center, Zhejiang Chinese Medical University , Hangzhou , China
| | - Jianchao Wang
- c Central Laboratory, The Second Clinical Medical College, Zhejiang Chinese Medical University , Hangzhou , China
| | - Minli Chen
- a Experimental Animal Research Center, Zhejiang Chinese Medical University , Hangzhou , China
| | - Huiying Fu
- c Central Laboratory, The Second Clinical Medical College, Zhejiang Chinese Medical University , Hangzhou , China
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167
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Pasiakos SM. Metabolic advantages of higher protein diets and benefits of dairy foods on weight management, glycemic regulation, and bone. J Food Sci 2015; 80 Suppl 1:A2-7. [PMID: 25757894 DOI: 10.1111/1750-3841.12804] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/17/2014] [Accepted: 11/17/2014] [Indexed: 01/23/2023]
Abstract
The Inst. of Medicine and World Health Organization have determined that 0.8 to 0.83 g protein·kg(-1) ·d(-1) is the quantity of protein required to establish nitrogen balance in nearly all healthy individuals. However, consuming higher protein diets may be metabolically advantageous, particularly for overweight and obese adults attempting weight loss, and for physically active individuals such as athletes and military personnel. Studies have demonstrated that higher protein diets may spare lean body mass during weight loss, promote weight management, enhance glycemic regulation, and increase intestinal calcium absorption, which may result in long-term improvements in bone health. The extent to which higher protein diets are beneficial is largely attributed to the digestive and absorptive properties, and also to the essential amino acid (EAA) content of the protein. Proteins that are rapidly digested and absorbed likely contribute to the metabolic advantages conferred by consuming higher protein diets. The EAA profiles, as well as the digestive and absorptive properties of dairy proteins, such as whey protein and casein, are particularly advantageous because they facilitate a rapid, robust, and sustained delivery of EAAs to the periphery. This article reviews the scientific literature assessing metabolic advantages associated with higher protein diets on weight management, glycemic regulation, and bone, with emphasis given to studies evaluating the potential benefits associated with dairy.
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Affiliation(s)
- Stefan M Pasiakos
- Military Nutrition Div, US Army Research Inst. of Environmental Medicine, Natick, MA, U.S.A
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168
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Abstract
Thermodynamics dictates that for body weight (i.e. stored substrate) loss to occur a person must ingest less energy than they expend. Athletes, who owing to their oftentimes large daily energy expenditures, may have greater flexibility than non-athletes in this regard; however, they may also have different goals for weight loss. In particular, weight lost may be less important to an athlete than from which compartment the weight is lost: fat or lean. A critical question is thus, what balance of macronutrients might promote a greater fat loss, a relative retention of lean mass, and still allow athletic performance to remain uncompromised? It is the central thesis of this review that dietary protein should be a nutrient around which changes in macronutrient composition should be framed. The requirement for protein to sustain lean mass increases while in negative energy balance and protein, as macronutrient, may have advantages with respect to satiety during energy balance, and it may allow greater fat loss during a negative energy balance. However, athletes should be mindful of the fact that increasing dietary protein intake while in negative energy balance would come at the ‘expense’ of another macronutrient. Most recently there has been interest in lower carbohydrate diets, which may not allow performance to be sustained given the importance of dietary carbohydrate in high-intensity exercise. The relative merits of higher protein diets for athletes are discussed.
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170
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Murphy CH, Churchward-Venne TA, Mitchell CJ, Kolar NM, Kassis A, Karagounis LG, Burke LM, Hawley JA, Phillips SM. Hypoenergetic diet-induced reductions in myofibrillar protein synthesis are restored with resistance training and balanced daily protein ingestion in older men. Am J Physiol Endocrinol Metab 2015; 308:E734-43. [PMID: 25738784 PMCID: PMC4420900 DOI: 10.1152/ajpendo.00550.2014] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 02/23/2015] [Indexed: 01/22/2023]
Abstract
Strategies to enhance weight loss with a high fat-to-lean ratio in overweight/obese older adults are important since lean loss could exacerbate sarcopenia. We examined how dietary protein distribution affected muscle protein synthesis during energy balance (EB), energy restriction (ER), and energy restriction plus resistance training (ER + RT). A 4-wk ER diet was provided to overweight/obese older men (66 ± 4 yr, 31 ± 5 kg/m(2)) who were randomized to either a balanced (BAL: 25% daily protein/meal × 4) or skewed (SKEW: 7:17:72:4% daily protein/meal; n = 10/group) pattern. Myofibrillar and sarcoplasmic protein fractional synthetic rates (FSR) were measured during a 13-h primed continuous infusion of l-[ring-(13)C6]phenylalanine with BAL and SKEW pattern of protein intake in EB, after 2 wk ER, and after 2 wk ER + RT. Fed-state myofibrillar FSR was lower in ER than EB in both groups (P < 0.001), but was greater in BAL than SKEW (P = 0.014). In ER + RT, fed-state myofibrillar FSR increased above ER in both groups and in BAL was not different from EB (P = 0.903). In SKEW myofibrillar FSR remained lower than EB (P = 0.002) and lower than BAL (P = 0.006). Fed-state sarcoplasmic protein FSR was reduced similarly in ER and ER + RT compared with EB (P < 0.01) in both groups. During ER in overweight/obese older men a BAL consumption of protein stimulated the synthesis of muscle contractile proteins more effectively than traditional, SKEW distribution. Combining RT with a BAL protein distribution "rescued" the lower rates of myofibrillar protein synthesis during moderate ER.
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Affiliation(s)
- Caoileann H Murphy
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | | | - Cameron J Mitchell
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Nathan M Kolar
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Amira Kassis
- Nestlé Research Center, Nestec, Lausanne, Switzerland
| | | | - Louise M Burke
- Department of Sports Nutrition, Australian Institute of Sport, Canberra, Australia
| | - John A Hawley
- Exercise and Nutrition Research Group, School of Exercise Science, Australian Catholic University, Fitzroy, Victoria, Australia; Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, United Kingdom; and
| | - Stuart M Phillips
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada;
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171
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Pasiakos SM, Lieberman HR, Fulgoni VL. Higher-protein diets are associated with higher HDL cholesterol and lower BMI and waist circumference in US adults. J Nutr 2015; 145:605-14. [PMID: 25733478 DOI: 10.3945/jn.114.205203] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Protein intake above the RDA attenuates cardiometabolic risk in overweight and obese adults during weight loss. However, the cardiometabolic consequences of consuming higher-protein diets in free-living adults have not been determined. OBJECTIVE This study examined usual protein intake [g/kg body weight (BW)] patterns stratified by weight status and their associations with cardiometabolic risk using data from the NHANES, 2001-2010 (n = 23,876 adults ≥19 y of age). METHODS Linear and decile trends for association of usual protein intake with cardiometabolic risk factors including blood pressure, glucose, insulin, cholesterol, and triglycerides were determined with use of models that controlled for age, sex, ethnicity, physical activity, poverty-income ratio, energy intake (kcal/d), carbohydrate (g/kg BW) and total fat (g/kg BW) intake, body mass index (BMI), and waist circumference. RESULTS Usual protein intake varied across deciles from 0.69 ± 0.004 to 1.51 ± 0.009 g/kg BW (means ± SEs). Usual protein intake was inversely associated with BMI (-0.47 kg/m(2) per decile and -4.54 kg/m(2) per g/kg BW) and waist circumference (-0.53 cm per decile and -2.45 cm per g/kg BW), whereas a positive association was observed between protein intake and HDL cholesterol (0.01 mmol/L per decile and 0.14 mmol/L per g/kg BW, P < 0.00125). CONCLUSIONS Americans of all body weights typically consume protein in excess of the RDA. Higher-protein diets are associated with lower BMI and waist circumference and higher HDL cholesterol compared to protein intakes at RDA levels. Our data suggest that Americans who consume dietary protein between 1.0 and 1.5 g/kg BW potentially have a lower risk of developing cardiometabolic disease.
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Affiliation(s)
- Stefan M Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA;
| | - Harris R Lieberman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA
| | - Victor L Fulgoni
- Oak Ridge Institute for Science and Education, Oak Ridge, TN; and Nutrition Impact LLC, Battle Creek, MI
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172
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Karl JP, Thompson LA, Niro PJ, Margolis LM, McClung JP, Cao JJ, Whigham LD, Combs GF, Young AJ, Lieberman HR, Pasiakos SM. Transient decrements in mood during energy deficit are independent of dietary protein-to-carbohydrate ratio. Physiol Behav 2015; 139:524-31. [DOI: 10.1016/j.physbeh.2014.11.068] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 11/21/2014] [Accepted: 11/25/2014] [Indexed: 01/31/2023]
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173
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Pasiakos SM, Margolis LM, Orr JS. Optimized dietary strategies to protect skeletal muscle mass during periods of unavoidable energy deficit. FASEB J 2014; 29:1136-42. [DOI: 10.1096/fj.14-266890] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 12/01/2014] [Indexed: 12/14/2022]
Affiliation(s)
- Stefan M. Pasiakos
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Lee M. Margolis
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
| | - Jeb S. Orr
- Military Nutrition DivisionU.S. Army Research Institute of Environmental MedicineNatickMassachusettsUSA
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174
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Leucine-enriched protein feeding does not impair exercise-induced free fatty acid availability and lipid oxidation: beneficial implications for training in carbohydrate-restricted states. Amino Acids 2014; 47:407-16. [DOI: 10.1007/s00726-014-1876-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 11/15/2014] [Indexed: 01/28/2023]
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175
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Margolis LM, Murphy NE, Martini S, Spitz MG, Thrane I, McGraw SM, Blatny JM, Castellani JW, Rood JC, Young AJ, Montain SJ, Gundersen Y, Pasiakos SM. Effects of winter military training on energy balance, whole-body protein balance, muscle damage, soreness, and physical performance. Appl Physiol Nutr Metab 2014; 39:1395-401. [DOI: 10.1139/apnm-2014-0212] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Physiological consequences of winter military operations are not well described. This study examined Norwegian soldiers (n = 21 males) participating in a physically demanding winter training program to evaluate whether short-term military training alters energy and whole-body protein balance, muscle damage, soreness, and performance. Energy expenditure (D218O) and intake were measured daily, and postabsorptive whole-body protein turnover ([15N]-glycine), muscle damage, soreness, and performance (vertical jump) were assessed at baseline, following a 4-day, military task training phase (MTT) and after a 3-day, 54-km ski march (SKI). Energy intake (kcal·day−1) increased (P < 0.01) from (mean ± SD (95% confidence interval)) 3098 ± 236 (2985, 3212) during MTT to 3461 ± 586 (3178, 3743) during SKI, while protein (g·kg−1·day−1) intake remained constant (MTT, 1.59 ± 0.33 (1.51, 1.66); and SKI, 1.71 ± 0.55 (1.58, 1.85)). Energy expenditure increased (P < 0.05) during SKI (6851 ± 562 (6580, 7122)) compared with MTT (5480 ± 389 (5293, 5668)) and exceeded energy intake. Protein flux, synthesis, and breakdown were all increased (P < 0.05) 24%, 18%, and 27%, respectively, during SKI compared with baseline and MTT. Whole-body protein balance was lower (P < 0.05) during SKI (–1.41 ± 1.11 (–1.98, –0.84) g·kg−1·10 h) than MTT and baseline. Muscle damage and soreness increased and performance decreased progressively (P < 0.05). The physiological consequences observed during short-term winter military training provide the basis for future studies to evaluate nutritional strategies that attenuate protein loss and sustain performance during severe energy deficits.
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Affiliation(s)
- Lee M. Margolis
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, 15 Kansas Street, Bldg. 42, Natick, MA 01760, USA
| | - Nancy E. Murphy
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, 15 Kansas Street, Bldg. 42, Natick, MA 01760, USA
| | - Svein Martini
- Norwegian Defence Research Establishment, Instituttvn 20, N-2007 Kjeller, Norway
| | - Marissa G. Spitz
- Thermal Mountain and Medicine Division, US Army Research Institute of Environmental Medicine, 15 Kansas Street, Bldg. 42, Natick, MA 01760, USA
| | - Ingjerd Thrane
- Norwegian Defence Research Establishment, Instituttvn 20, N-2007 Kjeller, Norway
| | - Susan M. McGraw
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, 15 Kansas Street, Bldg. 42, Natick, MA 01760, USA
| | - Janet-Martha Blatny
- Norwegian Defence Research Establishment, Instituttvn 20, N-2007 Kjeller, Norway
| | - John W. Castellani
- Thermal Mountain and Medicine Division, US Army Research Institute of Environmental Medicine, 15 Kansas Street, Bldg. 42, Natick, MA 01760, USA
| | - Jennifer C. Rood
- Pennington Biomedical Research Center, Louisiana State University System, 6400 Perkins Rd., Baton Rouge, LA 70808, USA
| | - Andrew J. Young
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, 15 Kansas Street, Bldg. 42, Natick, MA 01760, USA
| | - Scott J. Montain
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, 15 Kansas Street, Bldg. 42, Natick, MA 01760, USA
| | - Yngvar Gundersen
- Norwegian Defence Research Establishment, Instituttvn 20, N-2007 Kjeller, Norway
| | - Stefan M. Pasiakos
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, 15 Kansas Street, Bldg. 42, Natick, MA 01760, USA
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176
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Schoenfeld BJ, Aragon AA, Wilborn CD, Krieger JW, Sonmez GT. Body composition changes associated with fasted versus non-fasted aerobic exercise. J Int Soc Sports Nutr 2014; 11:54. [PMID: 25429252 PMCID: PMC4242477 DOI: 10.1186/s12970-014-0054-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 10/23/2014] [Indexed: 01/04/2023] Open
Abstract
It has been hypothesized that performing aerobic exercise after an overnight fast accelerates the loss of body fat. The purpose of this study was to investigate changes in fat mass and fat-free mass following four weeks of volume-equated fasted versus fed aerobic exercise in young women adhering to a hypocaloric diet. Twenty healthy young female volunteers were randomly assigned to 1 of 2 experimental groups: a fasted training (FASTED) group that performed exercise after an overnight fast (n = 10) or a post-prandial training (FED) group that consumed a meal prior to exercise (n = 10). Training consisted of 1 hour of steady-state aerobic exercise performed 3 days per week. Subjects were provided with customized dietary plans designed to induce a caloric deficit. Nutritional counseling was provided throughout the study period to help ensure dietary adherence and self-reported food intake was monitored on a regular basis. A meal replacement shake was provided either immediately prior to exercise for the FED group or immediately following exercise for the FASTED group, with this nutritional provision carried out under the supervision of a research assistant. Both groups showed a significant loss of weight (P = 0.0005) and fat mass (P = 0.02) from baseline, but no significant between-group differences were noted in any outcome measure. These findings indicate that body composition changes associated with aerobic exercise in conjunction with a hypocaloric diet are similar regardless whether or not an individual is fasted prior to training.
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Affiliation(s)
| | | | - Colin D Wilborn
- Exercise and Sport Science Department, University of Mary Hardin-Baylor, Belton, TX USA
| | | | - Gul T Sonmez
- Department of Health Science, Lehman College, Bronx, NY USA
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177
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Reljic D, Jost J, Dickau K, Kinscherf R, Bonaterra G, Friedmann-Bette B. Effects of pre-competitional rapid weight loss on nutrition, vitamin status and oxidative stress in elite boxers. J Sports Sci 2014; 33:437-48. [DOI: 10.1080/02640414.2014.949825] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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178
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Carbone JW, Pasiakos SM, Vislocky LM, Anderson JM, Rodriguez NR. Effects of short-term energy deficit on muscle protein breakdown and intramuscular proteolysis in normal-weight young adults. Appl Physiol Nutr Metab 2014; 39:960-8. [DOI: 10.1139/apnm-2013-0433] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of short-term energy deficit (ED) on direct measures of muscle proteolysis and the intracellular mechanisms by which muscle proteins are degraded at rest and following aerobic exercise are not well described. This study evaluated the effects of a short-term diet-induced ED, on muscle fractional breakdown rate (FBR), intramuscular 26S proteasome activity, caspase-3 activation, and PSMA2 and MAFbx expression at rest, in the postabsorptive state, and following a single bout of moderate aerobic exercise (45 min at 65% peak oxygen uptake). Six men and 4 women participated in two 10-day diet interventions: weight maintenance (WM) followed by ED (80% estimated energy requirements). Dietary protein (1.5 g·kg−1·day−1) intake was constant for WM and ED. Mixed muscle FBR, proteasome activity, and intracellular proteolytic factor expression were measured using stable isotope methodology, fluorescent enzyme activity assays, and Western blotting, respectively. Overall, FBR and caspase-3 activation increased 60% and 11%, respectively, in response to ED (P < 0.05), but were not influenced by exercise. During ED, 26S proteasome α-subunit PSMA2 expression was 25% higher (P < 0.05) after exercise compared with rest. Exercise did not influence PSMA2 expression during WM, and MAFbx expression and 26S proteasome activity were not affected by ED or exercise. These data illustrate the effects of short-term, moderate ED on muscle protein degradation. In the context of skeletal muscle integrity during weight loss interventions, this work demonstrates a need for further investigations aimed at mitigating muscle loss associated with energy deficit imposed for intentional reduction of total body weight.
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Affiliation(s)
- John W. Carbone
- School of Health Sciences, 312 Marshall Building, Eastern Michigan University, Ypsilanti, MI 48197, USA
| | - Stefan M. Pasiakos
- US Amy Research Institute of Environmental Medicine, Natick, MA 01760, USA
| | - Lisa M. Vislocky
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA
| | | | - Nancy R. Rodriguez
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA
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179
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Murphy CH, Hector AJ, Phillips SM. Considerations for protein intake in managing weight loss in athletes. Eur J Sport Sci 2014; 15:21-8. [DOI: 10.1080/17461391.2014.936325] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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180
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Gaffney-Stomberg E, Cao JJ, Lin GG, Wulff CR, Murphy NE, Young AJ, McClung JP, Pasiakos SM. Dietary protein level and source differentially affect bone metabolism, strength, and intestinal calcium transporter expression during ad libitum and food-restricted conditions in male rats. J Nutr 2014; 144:821-9. [PMID: 24717364 DOI: 10.3945/jn.113.188532] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
High-protein (HP) diets may attenuate bone loss during energy restriction. The objective of the current study was to determine whether HP diets suppress bone turnover and improve bone quality in male rats during food restriction and whether dietary protein source affects this relation. Eighty 12-wk-old male Sprague Dawley rats were randomly assigned to consume 1 of 4 study diets under ad libitum (AL) control or restricted conditions [40% food restriction (FR)]: 1) 10% [normal-protein (NP)] milk protein; 2) 32% (HP) milk protein; 3) 10% (NP) soy protein; or 4) 32% (HP) soy protein. After 16 wk, markers of bone turnover, volumetric bone mineral density (vBMD), microarchitecture, strength, and expression of duodenal calcium channels were assessed. FR increased bone turnover and resulted in lower femoral trabecular bone volume (P < 0.05), higher cortical bone surface (P < 0.001), and reduced femur length (P < 0.01), bending moment (P < 0.05), and moment of inertia (P = 0.001) compared with AL. HP intake reduced bone turnover and tended to suppress parathyroid hormone (PTH) (P = 0.06) and increase trabecular vBMD (P < 0.05) compared with NP but did not affect bone strength. Compared with milk, soy suppressed PTH (P < 0.05) and increased cortical vBMD (P < 0.05) and calcium content of the femur (P < 0.01) but did not affect strength variables. During AL conditions, transient receptor potential cation channel, subfamily V, member 6 was higher for soy than milk (P < 0.05) and HP compared with NP (P < 0.05). These data demonstrate that both HP and soy diets suppress PTH, and HP attenuates bone turnover and increases vBMD regardless of FR, although these differences do not affect bone strength. The effects of HP and soy may be due in part to enhanced intestinal calcium transporter expression.
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Affiliation(s)
- Erin Gaffney-Stomberg
- U.S. Army Research Institute of Environmental Medicine, Military Nutrition Division, Natick, MA; and
| | - Jay J Cao
- USDA Agricultural Research Service Grand Forks Human Nutrition Research Center, Grand Forks, ND
| | - Gregory G Lin
- U.S. Army Research Institute of Environmental Medicine, Military Nutrition Division, Natick, MA; and
| | - Charles R Wulff
- U.S. Army Research Institute of Environmental Medicine, Military Nutrition Division, Natick, MA; and
| | - Nancy E Murphy
- U.S. Army Research Institute of Environmental Medicine, Military Nutrition Division, Natick, MA; and
| | - Andrew J Young
- U.S. Army Research Institute of Environmental Medicine, Military Nutrition Division, Natick, MA; and
| | - James P McClung
- U.S. Army Research Institute of Environmental Medicine, Military Nutrition Division, Natick, MA; and
| | - Stefan M Pasiakos
- U.S. Army Research Institute of Environmental Medicine, Military Nutrition Division, Natick, MA; and
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181
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Antonio J, Peacock CA, Ellerbroek A, Fromhoff B, Silver T. The effects of consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals. J Int Soc Sports Nutr 2014; 11:19. [PMID: 24834017 PMCID: PMC4022420 DOI: 10.1186/1550-2783-11-19] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 04/11/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The consumption of dietary protein is important for resistance-trained individuals. It has been posited that intakes of 1.4 to 2.0 g/kg/day are needed for physically active individuals. Thus, the purpose of this investigation was to determine the effects of a very high protein diet (4.4 g/kg/d) on body composition in resistance-trained men and women. METHODS Thirty healthy resistance-trained individuals participated in this study (mean ± SD; age: 24.1 ± 5.6 yr; height: 171.4 ± 8.8 cm; weight: 73.3 ± 11.5 kg). Subjects were randomly assigned to one of the following groups: Control (CON) or high protein (HP). The CON group was instructed to maintain the same training and dietary habits over the course of the 8 week study. The HP group was instructed to consume 4.4 grams of protein per kg body weight daily. They were also instructed to maintain the same training and dietary habits (e.g. maintain the same fat and carbohydrate intake). Body composition (Bod Pod®), training volume (i.e. volume load), and food intake were determined at baseline and over the 8 week treatment period. RESULTS The HP group consumed significantly more protein and calories pre vs post (p < 0.05). Furthermore, the HP group consumed significantly more protein and calories than the CON (p < 0.05). The HP group consumed on average 307 ± 69 grams of protein compared to 138 ± 42 in the CON. When expressed per unit body weight, the HP group consumed 4.4 ± 0.8 g/kg/d of protein versus 1.8 ± 0.4 g/kg/d in the CON. There were no changes in training volume for either group. Moreover, there were no significant changes over time or between groups for body weight, fat mass, fat free mass, or percent body fat. CONCLUSIONS Consuming 5.5 times the recommended daily allowance of protein has no effect on body composition in resistance-trained individuals who otherwise maintain the same training regimen. This is the first interventional study to demonstrate that consuming a hypercaloric high protein diet does not result in an increase in body fat.
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Affiliation(s)
- Jose Antonio
- Exercise and Sports Sciences, Nova Southeastern University, 3532 S. University Drive, University Park Plaza Suite 3532, Davie, FL 33314, USA
| | - Corey A Peacock
- Exercise and Sports Sciences, Nova Southeastern University, 3532 S. University Drive, University Park Plaza Suite 3532, Davie, FL 33314, USA
| | - Anya Ellerbroek
- Exercise and Sports Sciences, Nova Southeastern University, 3532 S. University Drive, University Park Plaza Suite 3532, Davie, FL 33314, USA
| | - Brandon Fromhoff
- Exercise and Sports Sciences, Nova Southeastern University, 3532 S. University Drive, University Park Plaza Suite 3532, Davie, FL 33314, USA
| | - Tobin Silver
- Exercise and Sports Sciences, Nova Southeastern University, 3532 S. University Drive, University Park Plaza Suite 3532, Davie, FL 33314, USA
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182
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Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr 2014; 11:20. [PMID: 24864135 PMCID: PMC4033492 DOI: 10.1186/1550-2783-11-20] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 04/29/2014] [Indexed: 12/19/2022] Open
Abstract
The popularity of natural bodybuilding is increasing; however, evidence-based recommendations for it are lacking. This paper reviewed the scientific literature relevant to competition preparation on nutrition and supplementation, resulting in the following recommendations. Caloric intake should be set at a level that results in bodyweight losses of approximately 0.5 to 1%/wk to maximize muscle retention. Within this caloric intake, most but not all bodybuilders will respond best to consuming 2.3-3.1 g/kg of lean body mass per day of protein, 15-30% of calories from fat, and the reminder of calories from carbohydrate. Eating three to six meals per day with a meal containing 0.4-0.5 g/kg bodyweight of protein prior and subsequent to resistance training likely maximizes any theoretical benefits of nutrient timing and frequency. However, alterations in nutrient timing and frequency appear to have little effect on fat loss or lean mass retention. Among popular supplements, creatine monohydrate, caffeine and beta-alanine appear to have beneficial effects relevant to contest preparation, however others do not or warrant further study. The practice of dehydration and electrolyte manipulation in the final days and hours prior to competition can be dangerous, and may not improve appearance. Increasing carbohydrate intake at the end of preparation has a theoretical rationale to improve appearance, however it is understudied. Thus, if carbohydrate loading is pursued it should be practiced prior to competition and its benefit assessed individually. Finally, competitors should be aware of the increased risk of developing eating and body image disorders in aesthetic sport and therefore should have access to the appropriate mental health professionals.
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Affiliation(s)
- Eric R Helms
- Sport Performance Research in New Zealand (SPRINZ) at AUT Millennium Institute, AUT University, 17 Antares Place, Mairangi Bay, Auckland 0632, New Zealand
| | | | - Peter J Fitschen
- Division of Nutritional Sciences, University of Illinois, Urbana, IL, USA
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183
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Henning PC, Margolis LM, McClung JP, Young AJ, Pasiakos SM. High protein diets do not attenuate decrements in testosterone and IGF-I during energy deficit. Metabolism 2014; 63:628-32. [PMID: 24641883 DOI: 10.1016/j.metabol.2014.02.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 02/10/2014] [Accepted: 02/11/2014] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Energy deficit (ED) diminishes fat-free mass (FFM) with concomitant reductions in anabolic hormone secretion. A modest increase in protein to recommended dietary allowance (RDA) levels during ED minimally attenuates decrements in insulin-like growth factor-I (IGF-I). The impact of dietary protein above the RDA on circulating anabolic hormones and their relationships with FFM in response to ED are not well described. MATERIALS/METHODS Thirty-three adults were assigned diets providing protein at 0.8 (RDA), 1.6 (2×-RDA), and 2.4 (3×-RDA) g/kg/d for 31days. Testosterone, sex-hormone binding globulin (SHBG) and IGF-I system components were assessed after a 10-day period of weight-maintenance (WM) and after a 21-day period of ED (40%) achieved by an increase in energy expenditure and decreased energy intake. Associations between the change in FFM and anabolic hormone levels were determined. RESULTS As compared to WM and regardless of dietary protein intake, total and free testosterone, total IGF-I, and acid-labile subunit decreased (P<0.05), whereas SHBG and IGF binding proteins-1, -2, and -3 increased (P<0.05) during ED. There were no energy-by-protein interactions on any hormones or IGF-I system components measured. Changes in FFM in response to ED were negatively associated with acid-labile subunit (ALS) (r=-0.62, P<0.05) in 2×-RDA; however, no other relationships were observed. CONCLUSION Consuming a high protein diet does not impact the androgenic and IGF-I system response to ED. These data suggest that the protective effects of high protein diets on FFM during ED are likely not influenced by anabolic hormone concentrations.
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Affiliation(s)
- Paul C Henning
- Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - James P McClung
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Andrew J Young
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Stefan M Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA.
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184
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Areta JL, Burke LM, Camera DM, West DWD, Crawshay S, Moore DR, Stellingwerff T, Phillips SM, Hawley JA, Coffey VG. Reduced resting skeletal muscle protein synthesis is rescued by resistance exercise and protein ingestion following short-term energy deficit. Am J Physiol Endocrinol Metab 2014; 306:E989-97. [PMID: 24595305 DOI: 10.1152/ajpendo.00590.2013] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The myofibrillar protein synthesis (MPS) response to resistance exercise (REX) and protein ingestion during energy deficit (ED) is unknown. In young men (n = 8) and women (n = 7), we determined protein signaling and resting postabsorptive MPS during energy balance [EB; 45 kcal·kg fat-free mass (FFM)(-1)·day(-1)] and after 5 days of ED (30 kcal·kg FFM(-1)·day(-1)) as well as MPS while in ED after acute REX in the fasted state and with the ingestion of whey protein (15 and 30 g). Postabsorptive rates of MPS were 27% lower in ED than EB (P < 0.001), but REX stimulated MPS to rates equal to EB. Ingestion of 15 and 30 g of protein after REX in ED increased MPS ~16 and ~34% above resting EB (P < 0.02). p70 S6K Thr(389) phosphorylation increased above EB only with combined exercise and protein intake (~2-7 fold, P < 0.05). In conclusion, short-term ED reduces postabsorptive MPS; however, a bout of REX in ED restores MPS to values observed at rest in EB. The ingestion of protein after REX further increases MPS above resting EB in a dose-dependent manner. We conclude that combining REX with increased protein availability after exercise enhances rates of skeletal muscle protein synthesis during short-term ED and could in the long term preserve muscle mass.
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Affiliation(s)
- José L Areta
- Exercise and Nutrition Research Group, Health Innovations Research Institute, School of Medical Sciences, RMIT University, Melbourne, Australia
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185
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Calbet JAL, Ponce-González JG, Pérez-Suárez I, de la Calle Herrero J, Holmberg HC. A time-efficient reduction of fat mass in 4 days with exercise and caloric restriction. Scand J Med Sci Sports 2014; 25:223-33. [PMID: 24602091 DOI: 10.1111/sms.12194] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2014] [Indexed: 12/29/2022]
Abstract
To determine whether a fast reduction in fat mass can be achieved in 4 days by combining caloric restriction (CR: 3.2 kcal/kg body weight per day) with exercise (8-h walking + 45-min arm cranking per day) to induce an energy deficit of ∼5000 kcal/day, 15 overweight men underwent five experimental phases: pretest, exercise + CR for 4 days (WCR), control diet + reduced exercise for 3 days (DIET), and follow-up 4 weeks (POST1) and 1 year later (POST2). During WCR, the diet consisted solely of whey protein (n = 8) or sucrose (n = 7) (0.8 g/kg body weight per day). After WCR, DIET, POST1, and POST2, fat mass was reduced by a mean of 2.1, 2.8, 3.8, and 1.9 kg (P < 0.05), with two thirds of this loss from the trunk; and lean mass by 2.8, 1.0, 0.5, and 0.4 kg, respectively. After WCR, serum glucose, insulin, homeostatic model assessment, total and low-density lipoprotein cholesterol and triglycerides were reduced, and free fatty acid and cortisol increased. Serum leptin was reduced by 64%, 50%, and 33% following WCR, DIET, and POST1, respectively (P < 0.05). The effects were similar in both groups. In conclusion, a clinically relevant reduction in fat mass can be achieved in overweight men in just 4 days by combining prolonged exercise with CR.
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Affiliation(s)
- J A L Calbet
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Canary Islands, Spain; Instituto Universitario de Investigaciones Biomédicas y Sanitarias de la Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Canary Islands, Spain
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186
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Nutritional strategies for the preservation of fat free mass at high altitude. Nutrients 2014; 6:665-81. [PMID: 24531260 PMCID: PMC3942726 DOI: 10.3390/nu6020665] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 01/22/2014] [Accepted: 01/23/2014] [Indexed: 11/17/2022] Open
Abstract
Exposure to extreme altitude presents many physiological challenges. In addition to impaired physical and cognitive function, energy imbalance invariably occurs resulting in weight loss and body composition changes. Weight loss, and in particular, loss of fat free mass, combined with the inherent risks associated with extreme environments presents potential performance, safety, and health risks for those working, recreating, or conducting military operations at extreme altitude. In this review, contributors to muscle wasting at altitude are highlighted with special emphasis on protein turnover. The article will conclude with nutritional strategies that may potentially attenuate loss of fat free mass during high altitude exposure.
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187
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Moore DR, Camera DM, Areta JL, Hawley JA. Beyond muscle hypertrophy: why dietary protein is important for endurance athletes. Appl Physiol Nutr Metab 2014; 39:987-97. [PMID: 24806440 DOI: 10.1139/apnm-2013-0591] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Recovery from the demands of daily training is an essential element of a scientifically based periodized program whose twin goals are to maximize training adaptation and enhance performance. Prolonged endurance training sessions induce substantial metabolic perturbations in skeletal muscle, including the depletion of endogenous fuels and damage/disruption to muscle and body proteins. Therefore, increasing nutrient availability (i.e., carbohydrate and protein) in the post-training recovery period is important to replenish substrate stores and facilitate repair and remodelling of skeletal muscle. It is well accepted that protein ingestion following resistance-based exercise increases rates of skeletal muscle protein synthesis and potentiates gains in muscle mass and strength. To date, however, little attention has focused on the ability of dietary protein to enhance skeletal muscle remodelling and stimulate adaptations that promote an endurance phenotype. The purpose of this review is to critically discuss the results of recent studies that have examined the role of dietary protein for the endurance athlete. Our primary aim is to consider the results from contemporary investigations that have advanced our knowledge of how the manipulation of dietary protein (i.e., amount, type, and timing of ingestion) can facilitate muscle remodelling by promoting muscle protein synthesis. We focus on the role of protein in facilitating optimal recovery from, and promoting adaptations to strenuous endurance-based training.
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Affiliation(s)
- Daniel R Moore
- a Faculty of Kinesiology and Physical Education, University of Toronto, Toronto ON, M5S 2W6, Canada
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188
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Cao JJ, Pasiakos SM, Margolis LM, Sauter ER, Whigham LD, McClung JP, Young AJ, Combs GF. Calcium homeostasis and bone metabolic responses to high-protein diets during energy deficit in healthy young adults: a randomized controlled trial. Am J Clin Nutr 2014; 99:400-7. [PMID: 24284444 DOI: 10.3945/ajcn.113.073809] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Although consuming dietary protein above current recommendations during energy deficit (ED) preserves lean body mass, concerns have been raised regarding the effects of high-protein diets on bone health. OBJECTIVE The objective was to determine whether calcium homeostasis and bone turnover are affected by high-protein diets during weight maintenance (WM) and ED. DESIGN In a randomized, parallel-design, controlled trial of 32 men and 7 women, volunteers were assigned diets providing protein at 0.8 [Recommended Dietary Allowance (RDA)], 1.6 (2 × RDA), or 2.4 (3 × RDA) g · kg(-1) · d(-1) for 31 d. Ten days of WM preceded 21 d of ED, during which total daily ED was 40%, achieved by reduced dietary energy intake (∼30%) and increased physical activity (∼10%). The macronutrient composition (protein g · kg(-1) · d(-1) and % fat) was held constant from WM to ED. Calcium absorption (ratio of (44)Ca to (42)Ca) and circulating indexes of bone turnover were determined at day 8 (WM) and day 29 (ED). RESULTS Regardless of energy state, mean (±SEM) urinary pH was lower (P < 0.05) at 2 × RDA (6.28 ± 0.05) and 3 × RDA (6.23 ± 0.06) than at the RDA (6.54 ± 0.06). However, protein had no effect on either urinary calcium excretion (P > 0.05) or the amount of calcium retained (P > 0.05). ED decreased serum insulin-like growth factor I concentrations and increased serum tartrate-resistant acid phosphatase and 25-hydroxyvitamin D concentrations (P < 0.01). Remaining markers of bone turnover and whole-body bone mineral density and content were not affected by either the protein level or ED (P > 0.05). CONCLUSION These data demonstrate that short-term consumption of high-protein diets does not disrupt calcium homeostasis and is not detrimental to skeletal integrity. This trial was registered at www.clinicaltrials.gov as NCT01292395.
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Affiliation(s)
- Jay J Cao
- USDA, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND (JJC, LDW, and GFC); the Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA (SMP, LMM, JPM, and AJY); and the School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND (ERS)
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189
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Pasiakos SM, Montain SJ, Young AJ. Protein supplementation in U.S. military personnel. J Nutr 2013; 143:1815S-1819S. [PMID: 24027181 DOI: 10.3945/jn.113.175968] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Protein supplements (PSs) are, after multivitamins, the most frequently consumed dietary supplement by U.S. military personnel. Warfighters believe that PSs will improve health, promote muscle strength, and enhance physical performance. The estimated prevalence of regular PS use by military personnel is nearly 20% or more in active-duty personnel, which is comparable to collegiate athletes and recreationally active adults, but higher than that for average U.S. civilians. Although the acute metabolic effects of PS ingestion are well described, little is known regarding the benefits of PS use by warfighters in response to the metabolic demands of military operations. When dietary protein intake approaches 1.5 g · kg(-1) · d(-1), and energy intake matches energy expenditure, the use of PSs by most physically active military personnel may not be necessary. However, dismounted infantry often perform operations consisting of long periods of strenuous physical activity coupled with inadequate dietary energy and protein intake. In these situations, the use of PSs may have efficacy for preserving fat-free mass. This article reviews the available literature regarding the prevalence of PS use among military personnel. Furthermore, it highlights the unique metabolic stressors affecting U.S. military personnel and discusses potential conditions during which protein supplementation might be beneficial.
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Affiliation(s)
- Stefan M Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA
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