Exercise-trained men and women: role of exercise and diet on appetite and energy intake

Exercise increases TCA intermediate concentrations during low-calorie diet independent of insulin resistance among women with obesity

Tricarboxylic acid cycle intermediates (TCAi) have been proposed to act as myokines that influence energy metabolism. We determined if 2-weeks of low-calorie diet with interval exercise (LCD + INT) would increase TCAi more than a low-calorie diet (LCD). Twenty-three women were randomized to 2-weeks of LCD (n = 12, 48.4 ± 2.5 years, 37.8 ± 1.5 kg/m2, ~1200 kcal/d) or LCD + INT (n = 11, 47.6 ± 4.3 years, 37.9 ± 2.3 kg/m2; 60 min/d supervised INT of 3 min 90% & 50% HRpeak). TCAi and amino acids (AA) were measured at 0 min of a 75 g OGTT, while glucose, insulin, and FFA were obtained at 0, 30, 60, 90, 120, and 180 min to assess total area under the curve (tAUC180min) and insulin resistance (IR; tAUC180min of Glucose × Insulin). Fuel use (indirect calorimetry) was also collected at 0, 60, 120, and 180 min as was fitness (VO2peak) and body composition (BodPod). Treatments reduced weight (p < 0.001), fasting RER (p = 0.01), and IR (p = 0.03), although LCD + INT increased VO2peak (p = 0.02) and maintained RER tAUC180min (p = 0.05) versus LCD. Treatments increased FFA tAUC180min (p = 0.005), cis-aconitate, isocitrate, and succinate (p ≤ 0.02), as well as reduced phenylalanine and tryptophan, cysteine (p ≤ 0.005). However, LCD + INT increased malate, citrate, α-ketoglutarate, and alanine more than LCD (p ≤ 0.04). Thus, INT enhanced LCD effects on some TCAi in women with obesity independent of IR.

Amenorrhea and oligomenorrhea risk related to exercise training volume and intensity: Findings from 3705 participants recruited via the STRAVA™ exercise application

OBJECTIVES

To investigate associations between self-reported exercise training habits and amenorrhea/oligomenorrhea among physically active women.

DESIGN

A cross-sectional survey was completed by 3705 women (median age = 40 years [quartile 1, quartile 3: 30, 45], body mass index = 22.1 kg/m2 [20.5, 24.2]) representing multiple nationalities and sports via the STRAVA™ exercise application. Respondents selected the amount of time they participated in low intensity, moderate intensity, and high intensity exercise training per week. Amenorrhea/oligomenorrhea was defined as self-reporting ≤10 menses in the last year.

METHODS

Associations between weekly exercise volume for low intensity training, moderate intensity training, and high intensity training and amenorrhea/oligomenorrhea were modeled with univariate logistic regression models, followed by adjustment for age and body mass index.

RESULTS

Amenorrhea/oligomenorrhea prevalence was 16 % (n = 576/3705), with no difference by country of origin or most sport modes. In adjusted models, participating in low intensity training ≥7 h/week or moderate intensity training ≥6 h/week was associated with 1.43 (95 % confidence interval: 1.04-1.96) and 1.46 (1.10-1.95) greater odds of amenorrhea/oligomenorrhea compared to 2 to 3 h/week, respectively. Similarly, high intensity training ≥5 h/week was associated with 1.41 (1.03-1.92) greater odds of amenorrhea/oligomenorrhea compared to 1 to 2 h/week. Participating in low intensity training for ≤30 min/week compared to 2 to 3 h/week was associated with reduced amenorrhea/oligomenorrhea odds (0.65 [0.44-0.94]).

CONCLUSIONS

Taken together, these associations suggest greater weekly exercise volume, irrespective of intensity, may increase amenorrhea/oligomenorrhea risk among physically active women.

Neurocomputational mechanisms of food and physical activity decision-making in male adolescents

We examined the neurocomputational mechanisms in which male adolescents make food and physical activity decisions and how those processes are influenced by body weight and physical activity levels. After physical activity and dietary assessments, thirty-eight males ages 14-18 completed the behavioral rating and fMRI decision tasks for food and physical activity items. The food and physical activity self-control decisions were significantly correlated with each other. In both, taste- or enjoyment-oriented processes were negatively associated with successful self-control decisions, while health-oriented processes were positively associated. The correlation between taste/enjoyment and healthy attribute ratings predicted actual laboratory food intake and physical activities (2-week activity monitoring). fMRI data showed the decision values of both food and activity are encoded in the ventromedial prefrontal cortex, suggesting both decisions share common reward value-related circuits at the time of choice. Compared to the group with overweight/obese, the group with normal weight showed stronger brain activations in the cognitive control, multisensory integration, and motor control regions during physical activity decisions. For both food and physical activity, self-controlled decisions utilize similar computational and neurobiological mechanisms, which may provide insights into how to promote healthy food and physical activity decisions.

Acute effect of high-intensity interval training versus moderate-intensity continuous training on appetite perception: A systematic review and meta-analysis

Interval training protocols have gained popularity over the years, but their impact on appetite sensation compared to officially recommended training method, moderate intensity continuous training (MICT) is not well understood. Thus, this systematic review and meta-analysis aimed to compare a single session of high intensity interval training (HIIT) including sprint interval training (SIT) with MICT on appetite perception measured by the visual analog scale (VAS). After searching up articles published up to September 2021, 13 randomized controlled studies were included in the meta-analysis. Outcomes of meta-analysis demonstrated that both acute sessions of HIIT/SIT and MICT suppressed appetite compared to no-exercise control groups immediately post exercise but there were no significant effects 30-90 min post exercise or in AUC values, indicating a transient effect of exercise on appetite sensations. Moreover, differences in appetite sensations between HIIT/SIT and MICT were negligible immediately post exercise, but HIIT/SIT suppressed hunger (MD = -6.347 [-12.054, -0.639], p = 0.029) to a greater extent than MICT 30- to 90-min post exercise, while there was a lack of consistency other VAS subscales of appetite. More studies that address the impact of exercising timing, nutrient compositions of energy intake (energy intake (EI)) and differences in participants' characteristics and long-term studies analyzing chronic effects are needed to comprehensively examine the differences between HIIT/SIT and MICT on appetite and EI. SYSTEMATIC REVIEW REGISTRATION: [https://www.crd.york.ac.uk/PROSPERO], Identifier [CRD42021284898].

Plasma LEAP-2 Following a Low-Calorie Diet with or without Interval Exercise in Women with Obesity

Liver-expressed antimicrobial peptide-2 (LEAP-2) is associated with caloric intake and glucose metabolism. Purpose: Assess if a low-calorie diet with interval exercise (LCD+INT) raises LEAP-2 more than LCD in relation to appetite and cardiometabolic health. Methods: Women with obesity were randomized to either 2 weeks of LCD (n = 13, ~1200 kcal/d) or LCD+INT (n = 12; 60 min/d) of INT at 3 min of 90% and 50% HRpeak, respectively. LEAP-2 and acylated ghrelin (AG) were measured at 0, 30, and 60 min, while glucose, insulin, C-peptide, and free fatty acids (FFA) were obtained up to 180 min of a 75 g OGTT. Fasting and 120 min OGTT appetite were assessed via visual analog scales. Results: LCD reduced the BMI (p < 0.001) compared with LCD+INT, but only LCD+INT increased the VO2 max (p = 0.04). Treatments reduced fasting LEAP-2 (p = 0.05), but only LCD increased LEAP-2 iAUC60 min (p = 0.06) and post-prandial LEAP-2 stimulation (p = 0.02). Higher post-LEAP-260 min tended to relate to a lower desire to eat 120 min of sweet (r = 0.40, p = 0.07) and salty foods (r = 0.41, p = 0.06), as well as lower AG30 min (r = -0.51, p = 0.01) and higher FFA iAUC180 min (r = 0.56, p = 0.007) post-treatment. Conclusion: LCD, with or without INT, reduced fasting LEAP-2, but only LCD raised post-prandial LEAP-2. How diet and exercise impact LEAP-2 for lower chronic disease risk awaits further investigation.

Longitudinal associations between physical activity and other health behaviours during the COVID-19 pandemic: a fixed effects analysis

Government enforced restrictions on movement during the COVID-19 pandemic are likely to have had profound impacts on the daily behaviours of many individuals, including physical activity (PA). Given the associations between PA and other health behaviours, changes in PA during the pandemic may have been detrimental for other health behaviours. This study aimed to evaluate whether changes in PA during and after the first national lockdown in the United Kingdom (UK) were associated with concurrent changes in alcohol consumption, sleep, nutrition quality, diet quantity and sedentary time. Data were derived from the UCL COVID-19 Social Study, in which 52,784 adults were followed weekly across 22 weeks of the pandemic from 23rd March to 23rd August 2020. Fixed effects regression models showed that greater PA was positively associated with improved sleep and nutrition quality. However, increases in PA also showed modest associations with increased alcohol consumption and sedentary time. Encouraging people to engage in PA may lead to wider changes in other health behaviours in times of adversity. These associations could be a result of increases in available leisure time for many people during COVID-19 restrictions and are of ongoing importance given the emerging long-term changes to lifestyle and working patterns.

The Influence of FTO, FABP2, LEP, LEPR, and MC4R Genes on Obesity Parameters in Physically Active Caucasian Men

Obesity is a complex multifactorial abnormality that has a well-confirmed genetic basis. However, the problem still lies in identifying the polymorphisms linked to body mass and composition. Therefore, this study aimed to analyze associations between FTO (rs9939609), FABP2 (rs1799883), and LEP (rs2167270), LEPR (rs1137101), and MC4R (rs17782313) polymorphisms and obesity-related parameters. Unrelated Caucasian males (n = 165) were recruited. All participants had similar physical activity levels. The participants were divided into two groups depending on their body mass index (BMI) and fat mass index (FMI). All samples were genotyped using real-time polymerase chain reaction (real-time PCR). When tested individually, only one statistically significant result was found. The FTO A/T polymorphism was significantly associated with FMI (p = 0.01). The chance of having increased FMI was >2-fold higher for the FTO A allele carriers (p < 0.01). Gene−gene interaction analyses showed the additional influence of all investigated genes on BMI and FMI. In summary, it was demonstrated that harboring the FTO A allele might be a risk factor for elevated fat mass. Additionally, this study confirmed that all five polymorphisms are involved in the development of common obesity in the studied population and the genetic risk of obesity is linked to the accumulation of numerous variants.

Influence of Soldiers' Cardiorespiratory Fitness on Physiological Responses and Dropouts During a Loaded Long-distance March

INTRODUCTION

In military service, marching is an important, common, and physically demanding task. Minimizing dropouts, maintaining operational readiness during the march, and achieving a fast recovery are desirable because the soldiers have to be ready for duty, sometimes shortly after an exhausting task. The present field study investigated the influence of the soldiers' cardiorespiratory fitness on physiological responses during a long-lasting and challenging 34 km march.

MATERIALS AND METHODS

Heart rate (HR), body core temperature (BCT), total energy expenditure (TEE), energy intake, motivation, and pain sensation were investigated in 44 soldiers (20.3 ± 1.3 years, 178.5 ± 7.0 cm, 74.8 ± 9.8 kg, body mass index: 23.4 ± 2.7 kg × m-2, peak oxygen uptake ($\dot{\rm{V}}$O2peak): 54.2 ± 7.9 mL × kg-1 × min-1) during almost 8 hours of marching. All soldiers were equipped with a portable electrocardiogram to record HR and an accelerometer on the hip, all swallowed a telemetry pill to record BCT, and all filled out a pre- and post-march questionnaire. The influence of aerobic capacity on the physiological responses during the march was examined by dividing the soldiers into three fitness groups according to their $\dot{\rm{V}}$O2peak.

RESULTS

The group with the lowest aerobic capacity ($\dot{\rm{V}}$O2peak: 44.9 ± 4.8 mL × kg-1 × min-1) compared to the group with the highest aerobic capacity ($\dot{\rm{V}}$O2peak: 61.7 ± 2.2 mL × kg-1 × min-1) showed a significantly higher (P < .05) mean HR (133 ± 9 bpm and 125 ± 8 bpm, respectively) as well as peak BCT (38.6 ± 0.3 and 38.4 ± 0.2 °C, respectively) during the march. In terms of recovery ability during the break, no significant differences could be identified between the three groups in either HR or BCT. The energy deficit during the march was remarkably high, as the soldiers could only replace 22%, 26%, and 36% of the total energy expenditure in the lower, middle, and higher fitness group, respectively. The cardiorespiratory fittest soldiers showed a significantly higher motivation to perform when compared to the least cardiorespiratory fit soldiers (P = .002; scale from 1 [not at all] to 10 [extremely]; scale difference of 2.3). A total of nine soldiers (16%) had to end marching early: four soldiers (21%) in the group with the lowest aerobic capacity, five (28%) in the middle group, and none in the highest group.

CONCLUSION

Soldiers with a high $\dot{\rm{V}}$O2peak showed a lower mean HR and peak BCT throughout the long-distance march, as well as higher performance motivation, no dropouts, and lower energy deficit. All soldiers showed an enormous energy deficit; therefore, corresponding nutritional strategies are recommended.

Effects of menstrual cycle on appetite-regulating hormones and energy intake in response to cycling exercise in physically active women

Although ample evidence supports the notion that an acute bout of endurance exercise performed at or greater than 70% of maximum oxygen uptake suppresses appetite partly through changes in appetite-regulating hormones, no study has directly compared the influence between the phases of the menstrual cycle in women. The present study compared the effects of an acute bout of exercise on orexigenic hormone (acylated ghrelin) and anorexigenic hormones (peptide YY and cholecystokinin) between the early follicular phase (FP) and the mid luteal phase (LP) of the menstrual cycle in physically active women. Ten healthy women (age, 20.6 ± 0.7 years) completed two 3.5-h trials in each menstrual phase. In both trials, participants performed cycling exercises at 70% of heart rate reserve (at a corresponding intensity to 70% of maximum oxygen uptake) for 60 min followed by 90 min of rest. Following 90 min of rest, participants were provided with an ad libitum meal for a fixed duration of 30 min. Blood samples and subjective appetite were collected and assessed before, during, immediately post-, 45 min post-, and 90 min post-exercise. The exercise increased estradiol (327 %) and progesterone (681 %) in the LP more than the FP respectively (P < 0.001, f = 1.33; P < 0.001,f = 1.20). There were no between-trial differences in appetite-regulating hormones, subjective appetite, or energy intake of ad libitum meal. These findings indicate that exercise-induced increases in ovarian hormones in the LP may not influence appetite-regulating hormones in physically active women.

Effects of Isolated Soy Protein Supplementation Combined with Aerobic Exercise Training on Improving Body Composition, Anthropometric Characteristics and Cardiopulmonary Endurance in Women: A Pilot Study

Today, women are concerned with health promotion but also with improvements in body weight and shape. The purpose of this study was to investigate the effects of aerobic exercise training (AET) combined with isolated soy protein (ISP) supplementation on the body composition, anthropometric characteristics, and cardiopulmonary endurance of women. The qualified subjects were randomly assigned to AET or AET + ISP groups. Women in the AET + ISP group were given an ISP-rich supplement (40 g/day) 5 days a week for 8 weeks; those in the AET group were given the same amount of water in an identical manner. All women received 60 min of AET twice a week for 8 weeks at an intensity of 40–65% heart rate reserve (HRR) and their body composition, anthropometric characteristics, and physical fitness were measured one week before and after the 8-week AET class. A total of 16 subjects (age: 36.13 ± 5.76 years) completed the study and were included in the dataset. The results of this study show that the AET + ISP group obtained greater reductions in body weight (effect size = 0.99), body mass index (BMI, effect size = 1.04), percentage body fat (PBF, effect size = 1.18), circumferences (waist and hip, all effect sizes > 0.8), and greater gains in the percentage lean body mass (PLBM, effect size = 0.89), compared with the AET group, without significant differences in 20 m multi-stage shuttle run test (20 m MST). We conclude that there is a trend for the consumption of ISP following AET to improve the body composition and anthropometric characteristics in women, compared with those who received the same AET without ISP supplementation.

Planned morning aerobic exercise in a fasted state increases energy intake in the preceding 24 h

Purpose

We previously observed increased energy intake (EI) at the meal before planned afternoon exercise, but the proximity of the meal to exercise might have reduced the scale of the pre-exercise anticipatory eating. Therefore, this study examined EI in the 24 h before fasted morning exercise.

Methods

Fourteen males, experienced with gym-based aerobic exercise (age 25 ± 5 years, BMI 23.8 ± 2.5 kg/m²), completed counterbalanced exercise (EX) and resting (REST) trials. On day 1, subjects were told the following morning’s activity (EX/REST), before eating ad-libitum laboratory-based breakfast and lunch meals and a home-based afternoon/evening food pack. The following morning, subjects completed 30-min cycling and 30-min running (EX; 3274 ± 278 kJ) or 60-min supine rest (REST; 311 ± 34 kJ) fasted. Appetite was measured periodically, and EI quantified.

Results

Afternoon/evening EI (EX 7371 ± 2176 kJ; REST 6437 ± 2070 kJ; P = 0.017) and total 24-h EI (EX 14,055 ± 3672 kJ; REST 12,718 ± 3379 kJ; P = 0.011) were greater during EX, with no difference between trials at breakfast (P = 0.761) or lunch (P = 0.071). Relative EI (EI minus energy expended through EX/REST) was lower in EX (EX 10,781 ± 3539 kJ; REST 12,407 ± 3385 kJ; P = 0.004).

Conclusion

This study suggests planned fasted aerobic exercise increases EI during the preceding afternoon/evening, precipitating a ~ 10% increase in EI in the preceding 24-h. However, this increase did not fully compensate for energy expended during exercise; meaning exercise induced an acute negative energy balance.

Cold-Water Effects on Energy Balance in Healthy Women During Aqua-Cycling

BACKGROUND

While the popularity of aquatic physical activities continues to grow among women, the effects on energy expenditure (EE) and appetite control remain unknown. The objective of this study was to examine the effect of water temperature during aqua-cycling session on EE, rate of perceived exertion, energy intake, appetite sensations, and food reward in healthy premenopausal women.

METHODS

Participants completed three experimental sessions, in the postprandial condition, in a randomized order: a land control session (CON), an aqua-cycling session in 18 °C (EXO18), and an aqua-cycling session in 27 °C (EXO27). The EE, food intake, appetite sensations, and food reward were investigated for each condition.

RESULTS

EXO18 induced a significant increase in EE (p < .001) and oxygen consumption (p < .01) compared with EXO27. The carbohydrate oxidation was higher in EXO18 session compared with EXO27 and CON (p < .05 and p < .001, respectively). While fat oxidation was higher in exercise sessions compared with CONT (p < .01), no difference was observed between EXO18 and EXO27. Exercise sessions did not alter absolute energy intake session but induced a decrease in relative energy intake (p < .001) and in hunger, desire to eat, and prospective food consumption compared with CON (p < .001). The authors also show here that cold-water exposure can increase EE while rate of perceived exertion is lower at the end of exercise session compared with same exercise at 27 °C (p < .05).

CONCLUSION

An exposure to a moderately cold-water during aqua-cycling is an efficient strategy to promote increased EE and decreased hunger, which may be effective for energy balance management in healthy premenopausal women.

Short-term interval exercise suppresses acylated ghrelin and hunger during caloric restriction in women with obesity

Caloric restriction is suggested to increase hunger, in part, through complex interactions of hormones and behavior that contribute to challenges in long-term weight loss. Although intense exercise may attenuate appetite, no data exist testing the effects of interval exercise (INT) during a low-calorie diet (LCD) on appetite regulation. We hypothesized that LCD+INT would favorably influence satiety when compared with an energy-deficit matched LCD in women with obesity. Twenty-six women with obesity (47.3±2.4 yrs; 37.3 ± 1.2 kg/m2) were randomized to either LCD (n = 13; mixed meals of ~1200 kcal/d) or LCD+INT (n = 13; 60 min/d of supervised interval exercise at 90% HRpeak for 3 min and 50% HRpeak for 3 min) for 2 weeks. An additional 350kcal (shake) was provided to LCD+INT individuals post-exercise to equate energy availability between groups. Total PYY, acylated ghrelin and des-ghrelin were measured at 0, 30 and 60 min of a 75g OGTT before and after the intervention. Visual analog scales were also administered at 0 and 120 min of the OGTT to assess appetite perception. Food logs were recorded prior to and during the intervention to ensure caloric intake compliance. Compared with pre-intervention conditions, both interventions decreased food intake (P = 0.001) and body fat (P < 0.01). There was no effect on fasting PYY, but both LCD and LCD+INT increased post-prandial PYY iAUC (P < 0.001) relative to pre-intervention. LCD+INT maintained fasting acylated ghrelin (P = 0.06) and suppressed post-prandial acylated ghrelin iAUC (P = 0.04) compared to LCD. Neither intervention impacted circulating des- ghrelin before or following the OGTT. Interestingly, LCD+INT attenuated fasting hunger and maintained fullness compared with LCD (P = 0.05 and P = 0.06, respectively). Taken together, interval exercise favors acylated ghrelin suppression and perception of hunger during a LCD in women with obesity.

Muscle Glycogen Content during Endurance Training under Low Energy Availability

PURPOSE

The present study investigated the effects of three consecutive days of endurance training under conditions of low energy availability (LEA) on the muscle glycogen content, muscle damage markers, endocrine regulation, and endurance capacity in male runners.

METHODS

Seven male long-distance runners (19.9 ± 1.1 yr, 175.6 ± 4.7 cm, 61.4 ± 5.3 kg, maximal oxygen uptake [V˙O2max]: 67.5 ± 4.3 mL·kg·min) completed two trials consisting of three consecutive days of endurance training under LEA (18.9 ± 1.9 kcal·kg FFM·d) or normal energy availability (NEA) (52.9 ± 5.0 kcal·kg FFM·d). The order of the two trials was randomized, with a 2-wk interval between trials. The endurance training consisted of 75 min of treadmill running at 70% of V˙O2max. Muscle glycogen content, respiratory gas variables, and blood and urine variables were measured in the morning for three consecutive days of training (days 1-3) and on the following morning after training (day 4). As an indication of endurance capacity, time to exhaustion at 19.0 ± 0.8 km·h to elicit 90% of V˙O2max was evaluated on day 4.

RESULTS

During the training period, body weight, fat-free mass, and skeletal muscle volume were significantly reduced in LEA (P = 0.02 for body weight and skeletal muscle volume, P = 0.01 for fat-free mass). Additionally, muscle glycogen content was significantly reduced in LEA (~30%, P < 0.001), with significantly lower values than those in NEA (P < 0.001). Time to exhaustion was not significantly different between the two trials (~20 min, P = 0.39).

CONCLUSIONS

Three consecutive days of endurance training under LEA decreased muscle glycogen content with lowered body weight. However, endurance capacity was not significantly impaired.

Integrative Review of Dietary Choice Revealed by fMRI: Considerations for Obesity Prevention and Weight-Loss Education

BACKGROUND

Emerging findings from neuroimaging studies investigating brain activity associated with dietary behavior are illuminating the interaction of biological and behavioral mechanisms that have implications for obesity prevention. Globally, A total of 1.9 billion adults are overweight, and 650 million are obese. Obesity and being overweight are major risk factors for chronic illness and death. Behaviorally based health interventions have had limited success in curbing the obesity epidemic. Greater understanding of brain responses to food cues will contribute to new knowledge and shape public health efforts in obesity prevention. However, an integration of this knowledge for obesity prevention education has not been published.

AIMS

This study links evidence generated from brain activation studies generated in response to diet and food images and highlights educational recommendations for nurses engaged in obesity prevention and weight-loss education.

METHODS

An integrative review of the literature was conducted using the MeSH keywords "magnetic resonance imaging," "diet," and "food images" in PubMed, MEDLINE Complete, CINAHL, and Cochrane databases from their first appearance in 2006 through March 2018. Studies published in English and using functional magnetic resonance imaging to measure brain response to diet, and food images were initially identified. Animal models, those whose primary focus was a specific disease, and intervention studies were excluded.

RESULTS

Of 159 studies identified, 26 met inclusion criteria. Findings from neuroimaging studies may help explain the relationship between brain mechanisms and behavioral aspects of dietary choice and inform patient education in obesity prevention. Awareness of this evidence is applicable to nursing education efforts. This review contributes several recommendations that should be considered by nurses providing individualized weight-loss education.

LINKING EVIDENCE TO ACTION

Nurses engaged in patient education for obesity prevention should consider personalized interventions that cultivate internal awareness for dietary adherence, self-care, exercise, hydration, and mood state; avoid using caloric deprivation approaches, such as skipping breakfast, for weight-loss interventions; and note the importance of individualized obesity prevention and weight-loss education.

Impact of different exercise training modalities on energy and nutrient intake and food consumption in sedentary middle-aged adults: a randomised controlled trial

BACKGROUND

Exercise could influence energy and macronutrient intake, which could have an important role on body composition changes in response to exercise. The present study aimed to investigate the effects of different training modalities in energy and macronutrient intake, and whether changes in energy and macronutrient intake influences changes in body composition in response to different training modalities.

METHODS

A 12-week randomised controlled trial was conducted. Eighty middle-aged sedentary adults were randomised to: (i) a control group; (ii) physical activity recommendation from the World Health Organization; (iii) high-intensity interval training; and (iv) whole-body electromyostimulation training. Dietary intake was assessed using the average of three 24-h recalls.

RESULTS

High-intensity interval training and whole-body electromyostimulation training groups showed lower fibre intake and higher dietary energy density. Our results showed a negative association was found between changes in energy intake and changes in lean mass index. No association was found between changes in protein intake and changes in lean mass index.

CONCLUSIONS

In conclusion, we observed a higher dietary energy density and lower fibre intake in high-intensity training groups.

Swimming, but not vitamin E, ameliorates prothrombotic state and hypofibrinolysis in a rat model of nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is associated with a systemic procoagulant hypofibrinolysis state that is considered as a risk factor for microangiopathy and peripheral vascular diseases. Swimming exercise ameliorates the metabolic dysfunction in type 2 diabetes. Vitamin E is a natural antioxidant that reduces the risk of endothelial dysfunction in metabolic syndrome. The aim of the present study is to investigate the effect of combined swimming exercise with vitamin E on coagulation as well as blood fibrinolysis markers in rats with NAFLD.

METHODS

Eighty male rats were divided into control, control+vitamin E, control+exercise, high-fat diet (HFD), HFD+vitamin E, HFD+exercise, and HFD+vitamin E+exercise groups. Glucose, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), triglycerides, cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL), alanine transaminase (ALT) and aspartate transaminase (AST), intercellular adhesion molecule (ICAM-1), vascular cell adhesion molecule (VCAM-1), endothelin-1, von Willebrand factor (vWF), fibrinogen, plasminogen activator inhibitor (PAI-1), fibrin degradation products (FDP), platelet count and aggregation, bleeding and clotting times, activated partial thromboplastin time (aPTT), and prothrombin time (PT) were determined.

RESULTS

HFD increased lipid profile, insulin, glucose, HOMA-IR, liver enzymes, adhesion molecules, endothelin-1, vWF, platelet aggregation, fibrinogen, FDP, and PAI-1, and decreased clotting and bleeding times and HDL. Although exercise reduced lipid profile, glucose, insulin, HOMA-IR, vWF, platelet aggregation, fibrinogen, FDP, and PAI-1 and increased PT, aPTT, bleeding and clotting times, and HDL, vitamin E had no effect.

CONCLUSIONS

Exercise, but not vitamin E, ameliorated the HFD-induced prothrombotic state and enhanced fibrinolytic activity.

Post-Exercise Whole Body Cryotherapy (-140 °C) Increases Energy Intake in Athletes

PURPOSE

The purpose of the present study was to investigate the effect of whole-body cryotherapy (WBC) treatment after exercise on appetite regulation and energy intake.

METHODS

Twelve male athletes participated in two trials on different days. In both trials, participants performed high-intensity intermittent exercise. After 10 min following the completion of the exercise, they were exposed to a 3-min WBC treatment (-140 °C, WBC trial) or underwent a rest period (CON trial). Blood samples were collected to assess plasma acylated ghrelin, serum leptin, and other metabolic hormone concentrations. Respiratory gas parameters, skin temperature, and ratings of subjective variables were also measured after exercise. At 30 min post-exercise, energy and macronutrient intake were evaluated during an ad libitum buffet meal test.

RESULTS

Although appetite-regulating hormones (acylated ghrelin and leptin) significantly changed with exercise (p = 0.047 for acylated ghrelin and p < 0.001 for leptin), no significant differences were observed between the trials. Energy intake during the buffet meal test was significantly higher in the WBC trial (1371 ± 481 kcal) than the CON trial (1106 ± 452 kcal, p = 0.007).

CONCLUSION

Cold exposure using WBC following strenuous exercise increased energy intake in male athletes.

Acute effects of exercise intensity on subsequent substrate utilisation, appetite, and energy balance in men and women

Exercise is capable of influencing the regulation of energy balance by acutely modulating appetite and energy intake coupled to effects on substrate utilization. Yet, few studies have examined acute effects of exercise intensity on aspects of both energy intake and energy metabolism, independently of energy cost of exercise. Furthermore, little is known as to the gender differences of these effects. One hour after a standardised breakfast, 40 (19 female), healthy participants (BMI 23.6 ± 3.6 kg·m−2, V̇O2peak 34.4 ± 6.8 mL·kg−1·min−1) undertook either high-intensity intermittent cycling (HIIC) consisting of 8 repeated 60 s bouts of cycling at 95% V̇O2peak or low-intensity continuous cycling (LICC), equivalent to 50% V̇O2peak, matched for energy cost (∼950 kJ) followed by 90 mins of rest, in a randomised crossover design. Throughout each study visit, satiety was assessed subjectively using visual analogue scales alongside blood metabolites and GLP-1. Energy expenditure and substrate utilization were measured over 75 min postexercise via indirect calorimetry. Energy intake was assessed for 48 h postintervention. No differences in appetite, GLP-1, or energy intakes were observed between HIIC and LICC, with or without stratifying for gender. Significant differences in postexercise nonesterified fatty acid concentrations were observed between intensities in both genders, coupled to a significantly lower respiratory exchange ratio following HIIC (P = 0.0028), with a trend towards greater reductions in respiratory exchange ratioin males (P = 0.079). In conclusion, high-intensity exercise, if energy matched, does not lead to greater appetite or energy intake, but may exert additional beneficial metabolic effects that may be more pronounced in males.

Ovarian hormones and obesity

BACKGROUND

Obesity is caused by an imbalance between energy intake, i.e. eating and energy expenditure (EE). Severe obesity is more prevalent in women than men worldwide, and obesity pathophysiology and the resultant obesity-related disease risks differ in women and men. The underlying mechanisms are largely unknown. Pre-clinical and clinical research indicate that ovarian hormones may play a major role.

OBJECTIVE AND RATIONALE

We systematically reviewed the clinical and pre-clinical literature on the effects of ovarian hormones on the physiology of adipose tissue (AT) and the regulation of AT mass by energy intake and EE.

SEARCH METHODS

Articles in English indexed in PubMed through January 2016 were searched using keywords related to: (i) reproductive hormones, (ii) weight regulation and (iii) central nervous system. We sought to identify emerging research foci with clinical translational potential rather than to provide a comprehensive review.

OUTCOMES

We find that estrogens play a leading role in the causes and consequences of female obesity. With respect to adiposity, estrogens synergize with AT genes to increase gluteofemoral subcutaneous AT mass and decrease central AT mass in reproductive-age women, which leads to protective cardiometabolic effects. Loss of estrogens after menopause, independent of aging, increases total AT mass and decreases lean body mass, so that there is little net effect on body weight. Menopause also partially reverses women's protective AT distribution. These effects can be counteracted by estrogen treatment. With respect to eating, increasing estrogen levels progressively decrease eating during the follicular and peri-ovulatory phases of the menstrual cycle. Progestin levels are associated with eating during the luteal phase, but there does not appear to be a causal relationship. Progestins may increase binge eating and eating stimulated by negative emotional states during the luteal phase. Pre-clinical research indicates that one mechanism for the pre-ovulatory decrease in eating is a central action of estrogens to increase the satiating potency of the gastrointestinal hormone cholecystokinin. Another mechanism involves a decrease in the preference for sweet foods during the follicular phase. Genetic defects in brain α-melanocycte-stimulating hormone-melanocortin receptor (melanocortin 4 receptor, MC4R) signaling lead to a syndrome of overeating and obesity that is particularly pronounced in women and in female animals. The syndrome appears around puberty in mice with genetic deletions of MC4R, suggesting a role of ovarian hormones. Emerging functional brain-imaging data indicates that fluctuations in ovarian hormones affect eating by influencing striatal dopaminergic processing of flavor hedonics and lateral prefrontal cortex processing of cognitive inhibitory controls of eating. There is a dearth of research on the neuroendocrine control of eating after menopause. There is also comparatively little research on the effects of ovarian hormones on EE, although changes in ovarian hormone levels during the menstrual cycle do affect resting EE.

WIDER IMPLICATIONS

The markedly greater obesity burden in women makes understanding the diverse effects of ovarian hormones on eating, EE and body adiposity urgent research challenges. A variety of research modalities can be used to investigate these effects in women, and most of the mechanisms reviewed are accessible in animal models. Therefore, human and translational research on the roles of ovarian hormones in women's obesity and its causes should be intensified to gain further mechanistic insights that may ultimately be translated into novel anti-obesity therapies and thereby improve women's health.

Dynamic Energy Balance: An Integrated Framework for Discussing Diet and Physical Activity in Obesity Prevention-Is it More than Eating Less and Exercising More?

Understanding the dynamic nature of energy balance, and the interrelated and synergistic roles of diet and physical activity (PA) on body weight, will enable nutrition educators to be more effective in implementing obesity prevention education. Although most educators recognize that diet and PA are important for weight management, they may not fully understand their impact on energy flux and how diet alters energy expenditure and energy expenditure alters diet. Many nutrition educators have little training in exercise science; thus, they may not have the knowledge essential to understanding the benefits of PA for health or weight management beyond burning calories. This paper highlights the importance of advancing nutrition educators’ understanding about PA, and its synergistic role with diet, and the value of incorporating a dynamic energy balance approach into obesity-prevention programs. Five key points are highlighted: (1) the concept of dynamic vs. static energy balance; (2) the role of PA in weight management; (3) the role of PA in appetite regulation; (4) the concept of energy flux; and (5) the integration of dynamic energy balance into obesity prevention programs. The rationale for the importance of understanding the physiological relationship between PA and diet for effective obesity prevention programming is also reviewed.

Vegetarian, Gluten-Free, and Energy Restricted Diets in Female Athletes

Female athletes who follow a diet that fails to meet energy and nutrient needs are at risk for musculoskeletal injuries, menstrual disturbances, and poor sports performance. Common nutritional concerns for the female athlete include low energy availability (EA) (i.e., energy intake from food remaining for metabolic processes after accounting for energy expended during exercise) and inadequate dietary intakes (i.e., not meeting sports nutrition guidelines) of carbohydrates, protein, essential fatty acids (EFAs), B-vitamins, calcium, iron, and vitamin D. Low EA and the associated nutrient deficiencies are more common in athletes who compete in weight-sensitive sports (i.e., aesthetic, gravitational, and weight category sports) because low body fat and mass confer a competitive advantage. Other athletes at risk for energy and nutrient deficits include athletes following a vegetarian or gluten-free diet (GFD). Careful dietary planning can help an athlete meet energy and nutrient needs. This review covers the nutrition issues associated with low EA and special diets (i.e., vegetarian and GFD) and describes strategies to help female athletes meet their energy and nutrient needs.

Weight Management for Athletes and Active Individuals: A Brief Review

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.

The Effect of a Dairy-Based Recovery Beverage on Post-Exercise Appetite and Energy Intake in Active Females

This study was designed to assess the effect of a dairy-based recovery beverage on post-exercise appetite and energy intake in active females. Thirteen active females completed three trials in a crossover design. Participants completed 60 min of cycling at 65% V̇O2peak, before a 120 min recovery period. On completion of cycling, participants consumed a commercially available dairy-based beverage (DBB), a commercially available carbohydrate beverage (CHO), or a water control (H₂O). Non-esterified fatty acids, glucose, and appetite-related peptides alongside measures of subjective appetite were sampled at baseline and at 30 min intervals during recovery. At 120 min, energy intake was assessed in the laboratory by ad libitum assessment, and in the free-living environment by weighed food record for the remainder of the study day. Energy intake at the ad libitum lunch was lower after DBB compared to H₂O (4.43 ± 0.20, 5.58 ± 0.41 MJ, respectively; p = 0.046; (95% CI: -2.28, -0.20 MJ)), but was not different to CHO (5.21 ± 0.46 MJ), with no difference between trials thereafter. Insulin and GLP-17-36 were higher following DBB compared to H₂O (p = 0.015 and p = 0.001, respectively) but not to CHO (p = 1.00 and p = 0.146, respectively). In addition, glucagon was higher following DBB compared to CHO (p = 0.008) but not to H₂O (p = 0.074). The results demonstrate that where DBB consumption may manifest in accelerated recovery, this may be possible without significantly affecting total energy intake and subsequent appetite-related responses relative to a CHO beverage.

Associations between Bone Mineral Characteristics and Serum Levels of Ghrelin and Peptide YY in Overweight Adolescent Boys

BACKGROUND/AIMS

The role of ghrelin and peptide YY (PYY) in bone mineralization is not fully known. The aim of this study was to determine whether acylated and des-acyl ghrelin and PYY in addition to leptin are related to bone mineral density (BMD) in adolescent overweight boys (OWB) and normal-weight boys (NWB).

PARTICIPANTS AND METHODS

Fifty- five OWB (BMI >85th percentile) and 154 NWB (BMI <85th percentile) aged 12-16 years participated in this study. Fasting serum acylated and des-acyl ghrelin, PYY, leptin, testosterone levels, total body (TB) and lumbar spine (LS) bone mineral content (BMC), and BMD were measured. TB BMC for height and TB and LS bone mineral apparent density (BMAD) were calculated.

RESULTS

No differences were seen in acylated and des-acyl ghrelin or PYY levels, while the leptin levels were significantly higher in the OWB compared to the NWB. In the OWB, TB BMAD was positively correlated with acylated ghrelin and leptin, and TB BMC for height was positively correlated with PYY. In the OWB, the variability of TB BMD was determined by TB fat-free mass and des-acyl ghrelin, whereas the variability of TB BMAD was determined by leptin.

CONCLUSIONS

Des-acyl ghrelin and PYY are involved in the bone mineralization process in puberty, and the impact can vary between normal and overweight subjects.

A Pilot Study: Dietary Energy Density is Similar between Active Women with and without Exercise-Associated Menstrual Dysfunction

Low energy availability (EA) (e.g., insufficient energy intake (EI) to match energy needs, including exercise energy expenditure) has been identified as a primary contributor to exercise-associated menstrual dysfunction (ExMD) in active women. For health reasons, active women may self-select diets lower in energy density (ED, kcal/g), which can inadvertently contribute to inadequate EI. Using data from two studies, we compared the ED of active women with ExMD (n = 9; 24 ± 6 years) to eumenorrheic (EU) active controls (EU: n = 18, 27 ± 6 years). ED was calculated from 6 to 7 days weighted food records using two methods: with/without beverages. ANOVA and Wilcoxon Rank-Sum were used to test group differences. ED was not different between groups, but there was a trend toward a lower median ED (10%) (p = 0.049 unadjusted; p = 0.098 adjusted) in the ExMD-group (Method 1-all beverages: ExMD = 1.01 kcal/g (range = 0.52-1.41), EU = 1.22 kcal/g (range = 0.72-1.72); Method 2-without beverages: ExMD = 1.51 kcal/g (range = 1.26-2.06), EU = 1.69 kcal/g (range = 1.42-2.54)). This lower ED represents a 9% decrease (~219 kcal/day) in EI (ExMD = 2237 ± 378 kcal/day; EU = 2456 ± 470 kcal/day; p > 0.05). EI and macro/micronutrient intakes were similar for groups. In the ExMD-group, low ED could contribute to lower EI and EA. Future research should examine the interaction of ED and exercise on appetite, EI, and EA in active women, especially those with ExMD.

Ghrelin, food intake, and botanical extracts: A Review

A kind of growth hormone secretagogue (GHS), ghrelin, was first isolated from the rat stomach and plays a major role in the activation of the growth hormone secretagogue receptor 1a (GHS-R1a) resulting the release of growth hormone (GH). The preproghrelin gene is placed on chromosome 3, at locus 3p25 -2 in humans and constitutes five exons and three introns. Ghrelin is most plentifully expressed in particular cells in the oxyntic glands of the gastric epithelium, initially named X/A-like cells. Almost 60-70% of circulating ghrelin is secreted by the stomach. Plasma ghrelin concentration alters throughout the day. Ghrelin has been suggested to act as a meal initiator because of its appetite-stimulating influences in free feeding rats in short period. In addition to ghrelin's function as a meal motivator, it seems to contribute in long-term energy balance and nutritional status. In addition, many studies have been carried out in order to investigate the effects of natural and medicinal plants and botanical extracts on appetite, food intake, energy hemostasis, and the level of related hormones including ghrelin. Due to the importance of ghrelin in nutritional and medical sciences, this review was performed to understand new aspects of this hormone's function.