Acute Exercise and Hormones Related to Appetite Regulation: A Meta-Analysis

Exogenous Ketones Lower Post-exercise Acyl-Ghrelin and GLP-1 but Do Not Impact Ad libitum Energy Intake

Ketosis and exercise are both associated with alterations in perceived appetite and modification of appetite-regulating hormones. This study utilized a ketone ester (R)-3-hydroxybutyl (R)-3-hydroxybutyrate (KE) to examine the impact of elevated ketone body D-β-hydroxybutyrate (βHB) during and after a bout of exercise on appetite-related hormones, appetite perception, and ad libitum energy intake over a 2 h post-exercise period. In a randomized crossover trial, 13 healthy males and females (age: 23.6 ± 2.4 years; body mass index: 25.7 ± 3.2 kg·m⁻²) completed an exercise session @ 70% VO_2peak for 60 min on a cycling ergometer and consumed either: (1) Ketone monoester (KET) (0.5 g·kg⁻¹ pre-exercise + 0.25 g·kg⁻¹ post-exercise); or (2) isocaloric dextrose control (DEX). Transient ketonaemia was achieved with βHB concentrations reaching 5.0 mM (range 4.1–6.1 mM) during the post-exercise period. Relative to the dextrose condition, acyl-ghrelin (P = 0.002) and glucagon-like peptide-1 (P = 0.038) were both reduced by acute ketosis immediately following exercise. AUC for acyl-ghrelin was lower in KET compared to DEX (P = 0.001), however there were no differences in AUC for GLP-1 (P = 0.221) or PYY (P = 0.654). Perceived appetite (hunger, P = 0.388; satisfaction, P = 0.082; prospective food consumption, P = 0.254; fullness, P = 0.282) and 2 h post-exercise ad libitum energy intake (P = 0.488) were not altered by exogenous ketosis. Although KE modifies homeostatic regulators of appetite, it does not appear that KE acutely alters energy intake during the post-exercise period in healthy adults.

Effects of energy balance on appetite and physiological mediators of appetite during strenuous physical activity: secondary analysis of a randomised crossover trial

Energy deficit is common during prolonged periods of strenuous physical activity and limited sleep, but the extent to which appetite suppression contributes is unclear. The aim of this randomised crossover study was to determine the effects of energy balance on appetite and physiological mediators of appetite during a 72-h period of high physical activity energy expenditure (about 9·6 MJ/d (2300 kcal/d)) and limited sleep designed to simulate military operations (SUSOPS). Ten men consumed an energy-balanced diet while sedentary for 1 d (REST) followed by energy-balanced (BAL) and energy-deficient (DEF) controlled diets during SUSOPS. Appetite ratings, gastric emptying time (GET) and appetite-mediating hormone concentrations were measured. Energy balance was positive during BAL (18 (sd 20) %) and negative during DEF (–43 (sd 9) %). Relative to REST, hunger, desire to eat and prospective consumption ratings were all higher during DEF (26 (sd 40) %, 56 (sd 71) %, 28 (sd 34) %, respectively) and lower during BAL (–55 (sd 25) %, −52 (sd 27) %, −54 (sd 21) %, respectively; Pcondition < 0·05). Fullness ratings did not differ from REST during DEF, but were 65 (sd 61) % higher during BAL (Pcondition < 0·05). Regression analyses predicted hunger and prospective consumption would be reduced and fullness increased if energy balance was maintained during SUSOPS, and energy deficits of ≥25 % would be required to elicit increases in appetite. Between-condition differences in GET and appetite-mediating hormones identified slowed gastric emptying, increased anorexigenic hormone concentrations and decreased fasting acylated ghrelin concentrations as potential mechanisms of appetite suppression. Findings suggest that physiological responses that suppress appetite may deter energy balance from being achieved during prolonged periods of strenuous activity and limited sleep.

Associations between naturalistically assessed physical activity patterns, affect, and eating in youth with overweight and obesity

Insufficient physical activity (PA) and excessive stationary behavior (SB) are contributors to pediatric obesity, though antecedents and consequences of these behaviors in this population are relatively unknown. This pilot study examined affect, loss of control eating (LOCE), overeating, and hunger surrounding PA and SB in 17 youth with overweight/obesity. Participants completed a 14-day ecological momentary assessment (EMA) wearing accelerometers. At the momentary level, higher negative affect and lower positive affect predicted SB increases and PA decreases following EMA prompts; higher PA and lower SB also predicted increases in positive affect. Higher LOCE predicted SB increases and PA decreases, while increases in PA and decreases in SB predicted short-term increases in LOCE and overeating. At the individual level, higher SB and lower PA were related to lower positive affect and higher negative affect, LOCE, overeating, and hunger. Findings suggest affect is a relevant antecedent and consequence of PA/SB, and dysregulated eating may acutely impact PA/SB.

Zoladz J, Brzozowski T. Effect of Acute Sprint Exercise on Myokines and Food Intake Hormones in Young Healthy Men

Physical exercise is known to influence hormonal mediators of appetite, but the effect of short-term maximal intensity exercise on plasma levels of appetite hormones and cytokines has been little studied. We investigated the effect of a 30 s Wingate Test, followed by a postprandial period, on appetite sensations, food intake, and appetite hormones. Twenty-six physically active young males rated their subjective feelings of hunger, prospective food consumption, and fatigue on visual analogue scales at baseline, after exercise was completed, and during the postprandial period. Blood samples were obtained for the measurement of nesfatin-1, ghrelin, leptin, insulin, pancreatic polypeptide (PP), human growth factor (hGH) and cytokine interleukin-6 (IL-6), irisin and plasma lactate concentrations, at 30 min before exercise, immediately (210 s) after exercise, and 30 min following a meal and at corresponding times in control sedentary males without ad libitum meal intake, respectively. Appetite perceptions and food intake were decreased in response to exercise. Plasma levels of irisin, IL-6, lactate, nesfatin-1 and ghrelin was increased after exercise and then it was returned to postprandial/control period in both groups. A significant rise in plasma insulin, hGH and PP levels after exercise was observed while meal intake potentiated this response. In conclusion, an acute short-term fatiguing exercise can transiently suppress hunger sensations and food intake in humans. We postulate that this physiological response involves exercise-induced alterations in plasma hormones and the release of myokines such as irisin and IL-6, and supports the notion of existence of the skeletal muscle-brain-gut axis. Nevertheless, the detailed relationship between acute exercise releasing myokines, appetite sensations and impairment of this axis leading to several diseases should be further examined.

Assessment of the Dietary Intake of High-Rank Professional Male Football Players during a Preseason Training Week

A well-balanced diet is one of the main factors that may play a supportive role in enhancing acute training stimuli in optimal training adaptation. The aim of the present study was to examine the energy and macro- and micronutrient intake including and excluding supplements among top-level Polish football players during one week of the general preparatory period. In addition, the study looked at whether athletes consume carbohydrates in recommended amounts, depending on the completed training sessions. A total of 26 professional football players were included in the study. The preseason dietary intake was assessed using a 7-day estimated food record. The energy value of the diet and the amounts of the dietary ingredients were assessed using the software Dieta 6.0. The average consumption of energy, vitamin B₂, vitamin C, vitamin E, folate, and calcium was lower than recommendations, and average intake of sodium and potassium was higher than the norm in the diets of the athletes. The results of this study do not confirm the justification for adding protein preparations to diets of the studied players. Furthermore, football players dietary carbohydrate intake was relatively low in comparison to requirements based on training loads. Based on our results we conclude that further work is necessary to reinforce education about nutritional habits and adjust nutritional strategies to individual needs to enhance athletic performance.

Dietary Intake and Energy Expenditure During Two Different Phases of Athletic Training in Female Collegiate Lacrosse Players

Kumahara, H, Ohta, C, Nabeshima, E, Nakayama, A, Mine, S, and Yamato, T. Dietary intake and energy expenditure during two different phases of athletic training in female collegiate lacrosse players. J Strength Cond Res 34(6): 1547-1554, 2020-This study aims to investigate the state of nutrient intake and energy expenditure (EE) among various phases of periodization in female collegiate lacrosse players. A total of 17 Japanese female collegiate lacrosse players (age: 20.0 ± 0.9 years) were enrolled in this study. Physical activity (PA) and dietary intake were assessed over each 1-week period during the training preparatory phase (P-phase) and transition phase (T-phase). The exercise training-related EE (EEE) and EE associated with other daily living activities (i.e., nonexercise activity thermogenesis [NEAT]), were measured using accelerometers and heart rate (HR) monitoring using the flex-HR method. The total daily EE during the P-phase was significantly higher than that of the T-phase (2,168 ± 248 vs. 1744 ± 138 kcal·d; p < 0.01); however, no significant differences were observed in the total energy intake. Moreover, EEE during the P-phase was significantly higher than that of the T-phase, whereas no significant difference was found in NEAT. Furthermore, no significant differences were noted in any macronutrient intake variable observed between the 2 phases (protein:fat:carbohydrate ratio: 12.6 ± 1.5:32.9 ± 3.9:54.1 ± 5.1% in the P-phase vs. 12.1 ± 1.7:30.7 ± 3.9:55.7 ± 5.2% in the T-phase). The carbohydrate and protein intake were below recommended levels during the P-phase. Conversely, the saturated fatty acid ratio was higher than the dietary goals for disease prevention. Based on the changes in the PA volume observed during different training phases, female collegiate lacrosse players did not attain optimal nutrient intake required for optimal athletic performance and health.

Fundamental Concepts of Human Thermoregulation and Adaptation to Heat: A Review in the Context of Global Warming

The international community has recognized global warming as an impending catastrophe that poses significant threat to life on earth. In response, the signatories of the Paris Agreement (2015) have committed to limit the increase in global mean temperature to < 1.5 °C from pre-industry period, which is defined as 1950-1890. Considering that the protection of human life is a central focus in the Paris Agreement, the naturally endowed properties of the human body to protect itself from environmental extremes should form the core of an integrated and multifaceted solution against global warming. Scholars believe that heat and thermoregulation played important roles in the evolution of life and continue to be a central mechanism that allows humans to explore, labor and live in extreme conditions. However, the international effort against global warming has focused primarily on protecting the environment and on the reduction of greenhouse gases by changing human behavior, industrial practices and government policies, with limited consideration given to the nature and design of the human thermoregulatory system. Global warming is projected to challenge the limits of human thermoregulation, which can be enhanced by complementing innate human thermo-plasticity with the appropriate behavioral changes and technological innovations. Therefore, the primary aim of this review is to discuss the fundamental concepts and physiology of human thermoregulation as the underlying bases for human adaptation to global warming. Potential strategies to extend human tolerance against environmental heat through behavioral adaptations and technological innovations will also be discussed. An important behavioral adaptation postulated by this review is that sleep/wake cycles would gravitate towards a sub-nocturnal pattern, especially for outdoor activities, to avoid the heat in the day. Technologically, the current concept of air conditioning the space in the room would likely steer towards the concept of targeted body surface cooling. The current review was conducted using materials that were derived from PubMed search engine and the personal library of the author. The PubMed search was conducted using combinations of keywords that are related to the theme and topics in the respective sections of the review. The final set of articles selected were considered "state of the art," based on their contributions to the strength of scientific evidence and novelty in the domain knowledge on human thermoregulation and global warming.

A Time to Eat and a Time to Exercise

Analogous to exercise training, time-restricted eating may rescue some of the deleterious effects on metabolic health induced by our modern-day lifestyle.

This Perspective for Progress provides a synopsis for the potential of time-restricted eating (TRE) to rescue some of the deleterious effects on circadian biology induced by our modern-day lifestyle. We provide novel insights into the comparative and potential complementary effects of TRE and exercise training on metabolic health.

Caffeine increases whole-body fat oxidation during 1 h of cycling at Fatmax

PURPOSE

The ergogenic effect of caffeine on exercise of maximum intensity has been well established. However, there is controversy regarding the effect of caffeine on shifting substrate oxidation at submaximal exercise. The aim of this study was to investigate the effect of acute caffeine ingestion on whole-body substrate oxidation during 1 h of cycling at the intensity that elicits maximal fat oxidation (Fatmax).

METHODS

In a double-blind, randomized, and counterbalanced experiment, 12 healthy participants (VO_2max = 50.7 ± 12.1 mL/kg/min) performed two acute experimental trials after ingesting either caffeine (3 mg/kg) or a placebo (cellulose). The trials consisted of 1 h of continuous cycling at Fatmax. Energy expenditure, fat oxidation rate, and carbohydrate oxidation rate were continuously measured by indirect calorimetry.

RESULTS

In comparison to the placebo, caffeine increased the amount of fat oxidized during the trial (19.4 ± 7.7 vs 24.7 ± 9.6 g, respectively; P = 0.04) and decreased the amount of carbohydrate oxidized (94.6 ± 30.9 vs 73.8 ± 32.4 g; P = 0.01) and the mean self-perception of fatigue (Borg scale = 11 ± 2 vs 10 ± 2 arbitrary units; P = 0.05). In contrast, caffeine did not modify total energy expenditure (placebo = 543 ± 175; caffeine = 559 ± 170 kcal; P = 0.60) or mean heart rate (125 ± 13 and 127 ± 9 beats/min; P = 0.30) during exercise. Before exercise, caffeine increased systolic and diastolic blood pressure whilst it increased the feelings of nervousness and vigour after exercise (P < 0.05).

CONCLUSION

These results suggest that a moderate dose of caffeine (3 mg/kg) increases the amount of fat oxidized during 1 h of cycling at Fatmax. Thus, caffeine might be used as an effective strategy to enhance body fat utilization during submaximal exercise. The occurrence of several side effects should be taken into account when using caffeine to reduce body fat in populations with hypertension or high sensitivity to caffeine.

Effect of Physical Exercise on Taste Perceptions: A Systematic Review

The effect of physical exercise on nutrition has gained substantial interest in the last decade. Meaningful results have been produced concerning the effect of physical exercise on different appetite hormones and food choice/preference. While it is well known that taste and nutrition are related, the relation between taste and physical activity has not yet been fully explored. This systematic review aims to provide a detailed view of the literature on physical exercise and its effect on taste perceptions. Five tastes were included in this review: sweet, salty, bitter, sour, and umami. Sweet taste intensity, sensitivity, and preference were increased by acute physical exercise, but sweet preference was reduced by chronic physical activity. Perceived intensity and sensitivity decreased overall for salty taste, but an increased preference was noted during/following exercise. Sour taste intensity ratings were decreased following exercise and preference was enhanced. Umami taste intensity and sensitivity increased following exercise and preference was decreased. No significant results were obtained for bitter taste. While evidence regarding the effect of exercise on taste has arisen from this review, the pre-testing nutrition, testing conditions, type of test, and exercise modality must be standardized in order to produce meaningful and reproducible results in the future.

A Comparison of Intermittent and Continuous Exercise Bouts at Different Intensities on Appetite and Postprandial Metabolic Responses in Healthy Men

Exercise intensity affects many potential postprandial responses, but there is limited information on the influence of exercise modality. Therefore, the aim of this study was to investigate if the nature of exercise at two different intensities would affect gastric emptying rate (GER), appetite and metabolic responses following ingestion of a semi-solid meal. Twelve healthy men completed, in a random order, four 60-min cycles at 60% VO_2peak (MOD), 40% VO_2peak (LOW) and in a continuous (CON) or intermittent (INT) manner. INT consisted of 20 × 1-min exercise bouts with 2-min rest breaks. INT and CON were matched for total work output at each intensity. GER of the post-exercise meal was measured for 2 h using the 13C-breath method. Blood glucose, substrate utilisation and appetite ratings were measured at regular intervals throughout all trials and 24-h energy intake (EI) post-trials was assessed. GER-Delta over Baseline (DOB) was lower (p < 0.05) on MOD-INT vs. MOD-CON from 30–120 min post-meal. Blood glucose was higher mid-exercise (p < 0.05) on MOD-INT vs. MOD-CON. Although post-exercise LOW-CON was significantly higher than LOW-INT (p < 0.05), blood glucose was also higher 30-min post-meal ingestion on both CON trials compared to INT (p < 0.001). No interaction effect was observed for perceived appetite responses 2 h after meal ingestion (all p > 0.05). 24-h post-trial EI was similar between LOW-CON vs. LOW-INT (p > 0.05), although MOD-INT vs. MOD-CON 3500 ± 1419 vs. 2556 ± 989 kCal: p < 0.001 was elevated. In summary, MOD-INT exercise delays GER without stimulating perceived appetite in the 2 h period after meal ingestion, although EI was greater in the 24-h post-trial.

Physical Activity Promotes Health and Reduces Cardiovascular Mortality in Depressed Populations: A Literature Overview

Major depression is associated with premature mortality, largely explained by heightened cardiovascular burden. This narrative review summarizes secondary literature (i.e., reviews and meta-analyses) on this topic, considering physical exercise as a potential tool to counteract this alarming phenomenon. Compared to healthy controls, individuals with depression consistently present heightened cardiovascular risk, including "classical" risk factors and dysregulation of pertinent homeostatic systems (immune system, hypothalamic-pituitary-adrenal axis and autonomic nervous system). Ultimately, both genetic background and behavioral abnormalities contribute to explain the link between depression and cardiovascular mortality. Physical inactivity is particularly common in depressed populations and may represent an elective therapeutic target to address premature mortality. Exercise-based interventions, in fact, have proven effective reducing cardiovascular risk and mortality through different mechanisms, although evidence still needs to be replicated in depressed populations. Notably, exercise also directly improves depressive symptoms. Despite its potential, however, exercise remains under-prescribed to depressed individuals. Public health may be the ideal setting to develop and disseminate initiatives that promote the prescription and delivery of exercise-based interventions, with a particular focus on their cost-effectiveness.

Timing of Nutrient Ingestion after Mild to Moderate Cycling Exercise Does Not Affect Gastric Emptying Rate in Humans

This study examined the effect of carbohydrate drink ingestion timing on gastrointestinal tract blood flow and motility after mild cycling exercise. Eight healthy participants were randomly assigned to ingest a liquid solution with 75 g glucose at either 5 min (PE-5) or 30 min (PE-30) after a single bout of leg cycling exercise according to target heart rate (approximately 120 beats/min). As the control trial (Con), participants ingested the same liquid solution without exercise. Celiac artery blood flow (BF), superior mesenteric artery BF, and gastric emptying rate were assessed by ultrasonography before and for 60 min after ingesting the glucose solution. Blood lactate, glucose, and plasma insulin were also measured at baseline and for 60 min after ingesting the glucose solution. Celiac artery BF significantly decreased from resting baseline immediately after exercise in both the PE-5 and PE-30 trials, and then returned to resting baseline just before the ingestion of glucose solution in the PE-30 trial. After ingesting the glucose solution, changes in celiac artery BF, superior mesenteric artery BF, % gastric emptying rate, blood lactate, blood glucose, and plasma insulin were not significantly different among the three trials. The timing of nutrient ingestion after mild exercise does not seem to impact the subsequent gastrointestinal motility, blood flow, and glycemic responses.

The Impact of Physical Activity on Food Reward: Review and Conceptual Synthesis of Evidence from Observational, Acute, and Chronic Exercise Training Studies

PURPOSE OF REVIEW

This review brings together current evidence from observational, acute, and chronic exercise training studies to inform public debate on the impact of physical activity and exercise on food reward.

RECENT FINDINGS

Low levels of physical activity are associated with higher liking and wanting for high-energy food. Acute bouts of exercise tend to reduce behavioral indices of reward for high-energy food in inactive individuals. A dissociation in liking (increase) and wanting (decrease) may occur during chronic exercise training associated with loss of body fat. Habitual moderate-to-vigorous physical activity is associated with lower liking and wanting for high-fat food, and higher liking for low-fat food. Food reward does not counteract the benefit of increasing physical activity levels for obesity management. Exercise training appears to be accompanied by positive changes in food preferences in line with an overall improvement in appetite control.

Interindividual Variation in Cardiorespiratory Fitness: A Candidate Gene Study in Han Chinese People

Cardiorespiratory fitness, as assessed through peak oxygen uptake (VO2peak), is a powerful health indicator. We aimed to evaluate the influence of several candidate causal genetic variants on VO2peak level in untrained Han Chinese people. A total of 1009 participants (566 women; age [mean ± SD] 40 ± 14 years, VO2peak 29.9 ± 7.1 mL/kg/min) performed a maximal incremental cycling test for VO2peak determination. Genomic DNA was extracted from peripheral whole blood, and genotyping analysis was performed on 125 gene variants. Using age, sex, and body mass as covariates, and setting a stringent threshold p-value of 0.0004, only one single nucleotide polymorphism (SNP), located in the gene encoding angiotensin-converting enzyme (rs4295), was associated with VO2peak (β = 0.87; p < 2.9 × 10-4). Stepwise multiple regression analysis identified a panel of three SNPs (rs4295 = 1.1%, angiotensin II receptor type 1 rs275652 = 0.6%, and myostatin rs7570532 = 0.5%) that together accounted for 2.2% (p = 0.0007) of the interindividual variance in VO2peak. Participants carrying six 'favorable' alleles had a higher VO2peak (32.3 ± 8.1 mL/kg/min) than those carrying only one favorable allele (24.6 ± 5.2 mL/kg/min, p < 0.0001). In summary, VO2peak at the pre-trained state is partly influenced by several polymorphic variations in candidate genes, but they represent a minor portion of the variance.

Influence of postexercise fasting on hunger and satiety in adults

Research demonstrates that exercise acutely reduces appetite by stimulating the secretion of gut-derived satiety hormones. Currently there is a paucity of research examining the impact of postexercise nutrient intake on appetite regulation. The objective of this study was to examine how postexercise fasting versus feeding impacts the postexercise appetite response. In a randomized crossover intervention, 14 participants (body mass index: 26.9 ± 3.5 kg·m^-2; age: 26.8 ± 6.7 years) received 1 of 2 recovery beverages: (i) water control (FAST) or (ii) sweetened-milk (FED) after completing a 45-min (65%-70% peak oxygen uptake) evening exercise session (∼1900 h). Energy intake was assessed through a fasted ad libitum breakfast meal and 3-day food diaries. Perceived appetite was assessed using visual analogue scales. Appetite-regulating hormones glucagon-like peptide-1 (GLP-1), peptide tyrosine-tyrosine (PYY), and acyl-ghrelin were assessed pre-exercise, 1 h after exercise, and the morning following exercise. FAST increased subjective hunger compared with FED (P < 0.05). PYY and GLP-1 after exercise were decreased and acyl-ghrelin was increased in FAST, with these differences disappearing the day after exercise (P < 0.05). Ad libitum energy intake at breakfast the following morning did not differ between trials. Overall, in the absence of postexercise macronutrient consumption, there was a pronounced increase in objective and subjective appetite after exercise. The orexigenic effects of postexercise fasting, however, were not observed the morning following exercise. Novelty Postexercise fasting leads to reduced GLP-1 and PYY and increased hunger. Reduced GLP-1 and PYY after exercise is blunted by postexercise nutrient intake. Energy intake the day after exercise is not influenced by postexercise fasting.

Greater lactate accumulation following an acute bout of high-intensity exercise in males suppresses acylated ghrelin and appetite postexercise

High-intensity exercise inhibits appetite, in part, via alterations in the peripheral concentrations of the appetite-regulating hormones acylated ghrelin, active glucagon-like peptide-1 (GLP-1), and active peptide tyrosine-tyrosine (PYY). Given lactate may mediate these effects, we used sodium bicarbonate (NaHCO₃) supplementation in a double-blind, placebo-controlled, crossover design to investigate lactate's purported role in exercise-induced appetite suppression. Eleven males completed two identical high-intensity interval training sessions (10 × 1 min cycling bouts at ~90% heart rate maximum interspersed with 1-min recovery), where they ingested either NaHCO₃ (BICARB) or sodium chloride (NaCl) as a placebo (PLACEBO) preexercise. Blood lactate, acylated ghrelin, GLP-1, and PYY concentrations, as well as overall appetite were assessed preexercise and 0, 30, 60, and 90 min postexercise. Blood lactate was greater immediately (P < 0.001) and 30 min postexercise (P = 0.049) in the BICARB session with an increased (P = 0.009) area under the curve (AUC). The BICARB session had lower acylated ghrelin at 60 (P = 0.014) and 90 min postexercise (P = 0.016), with a decreased AUC (P = 0.039). The BICARB session had increased PYY (P = 0.034) with an increased AUC (P = 0.031). The BICARB session also tended (P = 0.060) to have increased GLP-1 at 30 (P = 0.003) and 60 min postexercise (P < 0.001), with an increased AUC (P = 0.030). The BICARB session tended (P = 0.059) to reduce overall appetite, although there was no difference in AUC (P = 0.149). These findings support a potential role for lactate in the high-intensity exercise-induced appetite-suppression.NEW & NOTEWORTHY We used sodium bicarbonate to increase lactate accumulation or sodium chloride as a placebo. Our findings further implicate lactate as a mediator of exercise-induced appetite suppression, given exercise-induced increases in lactate during the sodium bicarbonate session altered peripheral concentrations of appetite-regulating hormones, culminating in a reduction of appetite. This supports a lactate-dependent mechanism of appetite suppression following high-intensity exercise and highlights the potential of using lactate as a means of inducing a caloric deficit.

The Effects of the Type of Exercise and Physical Activity on Eating Behavior and Body Composition in Overweight and Obese Subjects

The aim of this study was to examine whether a type of exercise favors better compliance with a prescribed diet, higher eating-related motivation, healthier diet composition or greater changes in body composition in overweight and obese subjects. One hundred and sixty-two (males n = 79), aged 18-50 years, were randomized into four intervention groups during 24 weeks: strength, endurance, combined strength + endurance and guideline-based physical activity; all in combination with a 25-30% caloric restriction diet. A food frequency questionnaire and a "3-day food and drink record" were applied pre- and post-intervention. Diet and exercise-related motivation levels were evaluated with a questionnaire developed for this study. Body composition was assessed by DXA and habitual physical activity was measured by accelerometry. Body weight, body mass index (BMI) and body fat percentage decreased and lean body mass increased after the intervention, without differences by groups. No interactions were observed between intervention groups and time; all showing a decreased in energy intake (p < 0.001). Carbohydrate and protein intakes increased, and fat intake decreased from pre- to post-intervention without significant interactions with intervention groups, BMI category or gender (p < 0.001). Diet-related motivation showed a tendency to increase from pre- to post-intervention (70.0 ± 0.5 vs 71.0 ± 0.6, p = 0.053), without significant interactions with intervention groups, BMI or gender. Regarding motivation for exercise, gender x time interactions were observed (F(1,146) = 7.452, p = 0.007): Women increased their motivation after the intervention (pre: 17.6 ± 0.3, post: 18.2 ± 0.3), while men maintained it. These findings suggest that there are no substantial effects of exercise type on energy intake, macronutrient selection or body composition changes. After a six-month weight loss program, individuals did not reduce their motivation related to diet or exercise, especially women. Individuals who initiate a long-term exercise program do not increase their energy intake in a compensatory fashion, if diet advices are included.

Interactions of sprint interval exercise and psychological need-support on subsequent food intake among physically inactive men and women

The aim of this study was to investigate the effect of sprint interval training (SIT) and psychological need-support in exercise on postexercise appetite and energy intake. Forty physically inactive men and women (body mass index, 24.6 ± 4.8 kg·m^-2; peak oxygen consumption, 26.6 ± 4.9 mL·kg^-1·min^-1) were randomised to either a need-support or no-support condition, with each participant completing 2 experimental trials involving 30 min of moderate-intensity continuous training (MICT; 60% peak oxygen consumption) and SIT (alternating 15 s at 170% peak oxygen consumption and 60 s at 32% peak oxygen consumption) matched for total work. Perceptions of appetite and appetite-related blood variables were assessed, together with ad libitum energy intake for 3 h following exercise using a laboratory test meal and available snacks. Greater enjoyment, perceived exertion, heart rate, and blood lactate were observed in SIT compared with MICT (all p ≤ 0.006). Ratings of perceived appetite were similar across conditions and trials (p > 0.05); however, active ghrelin was lower following SIT compared with MICT (p < 0.001), and there was a significant condition-by-type interaction for energy intake (p = 0.033), with participants in the support group consuming less energy from foods following SIT (1895 ± 1040 kJ) than MICT (2475 ± 1192 kJ). Findings from this work highlight the need to reconsider traditional exercise guidelines where dietary intake is a concern. Novelty Enjoyment was greater during SIT compared with MICT. Enjoyment and choice were higher among participants provided with psychological need-support. In a need-supportive environment, SIT reduced subsequent energy intake compared with MICT.

Impact of Exercise Timing on Chemosensory Response, Appetite, and Energy Intake in Lean Males

BACKGROUND

High-intensity exercise can have an anorectic impact, leading to negative energy balance. Several studies have reported that the practice of physical activity could also cause a shift in perceptions and preferences, causing a change in food intakes.

OBJECTIVE

This study aimed to question to what extent the timing of exercise in relation to a meal could have an impact on olfaction and gustation, appetite, and food choices.

METHODS

Twelve males aged 25 (4) years with a body mass index of 22.4 (2.0) kg/m2 attended two experimental visits in a counterbalanced fashion. The participants consumed a standardized breakfast between 7:00 and 7:30 a.m. and were subjected to smell and taste tests upon arrival at the laboratory (8:30 a.m.). In the EX9:40 visit, the participants performed a 30-min exercise session (70% of maximum oxygen uptake) at 9:40 a.m., followed by a 90-min sedentary break. In EX10:30, the participants first took part in the 90-min sedentary break and then performed the 30-min exercise session at 10:30 a.m. Taste and smell tests were performed again at 11:40 a.m., immediately followed by an ad libitum buffet-style meal. Visual analog scales were used to report appetite sensations during the session and satiety quotients around the lunch.

RESULTS

There was no difference in energy intakes between the EX9:40 (596 [302] kcal) and EX10:30 (682 [263] kcal) conditions (p = .459). There was no condition effect for the taste and smell sensations (all ps > .05), appetite sensation, or satiety quotients around the meal (all ps > .05).

CONCLUSION

Exercise timing in the morning had no effect on taste and smell perceptions, appetite sensations, or energy intakes.

The effectiveness of a community-based exercise program on depression symptoms among people living with HIV

HIV is a worldwide public health issue affecting millions of individuals, and people living with HIV (PLWH) are often affected by depression. Nonetheless, exercise can prevent and treat depression among PLWH. The aim of the present study was to investigate the effect of exercise on depression symptoms in PLWH. Using a prospective single-arm trial, a semi-supervised community-based exercise intervention was offered 3 times/week for 12 weeks to PLWH (n = 52; age: 49 ± 6 years; HIV diagnosis: 19 ± 15 years). Participants were divided into compliant (≥1 exercise session/week) and non-compliant (<1 exercise session/week) groups according to their attendance in the intervention. Depression symptoms were assessed using the Beck Depression Inventory (BDI), and the change in BDI from baseline to post-intervention was assessed with an analysis of covariance, adjusted for demographics. The post-intervention BDI score was significantly lower (p = 0.027) for the compliant group compared to the non-compliant group, and the rate of improvement from moderate/severe symptoms of depression to minimal symptoms of depression was four times greater in the compliant group. In conclusion, a community-based exercise program may be effective in reducing depression symptoms among PLWH.

Effects of Exercise during Weight Loss Maintenance on Appetite Regulation in Women

Exercise is accepted as a method to improve weight loss maintenance; however, the mechanisms by which this occurs have yet to be elucidated. In this pilot study, 13 women with obesity underwent a structured weight loss program (goal 8%-10% weight loss) and were then randomized to either a 12-wk diet (n = 7) or an aerobic exercise training (n = 6) intervention aimed at maintaining weight loss. At baseline, post-weight loss, and following the weight loss maintenance interventions, measurements of appetite (hunger and satiety) and appetite-regulating hormones (leptin, ghrelin, peptide tyrosine tyrosine, and glucagon-like peptide 1) were obtained after an overnight fast and for 3 h after a standardized test meal. Ad libitum energy intake was measured at a lunch meal. During the weight loss phase, participants lost 9.1% ± 1.1% of baseline body weight. Participants in both groups maintained weight loss during the 12-wk weight loss maintenance intervention. No differences in fasting leptin (P = 0.68) or in ghrelin (P = 0.30), peptide tyrosine tyrosine (P = 0.93), and glucagon-like peptide 1 (P = 0.98) area under the curve were detected between groups. Similarly, ratings of hunger (P = 0.99) and satiety (P = 0.65) area under the curve after the standardized test meal also did not differ between the groups nor did ad libitum energy intake at lunch. In summary, the 12-wk diet and exercise interventions were equally effective at maintaining weight loss in women, and no differences in measures of appetite regulation and food intake were found.

Proceedings of the 2017 ASPEN Research Workshop-Gastric Bypass: Role of the Gut

The goal of the National Institutes of Health-funded American Society for Parenteral and Enteral Nutrition 2017 research workshop (RW) "Gastric Bypass: Role of the Gut" was to focus on the exciting research evaluating gut-derived signals in modulating outcomes after bariatric surgery. Although gastric bypass surgery has undoubted positive effects, the mechanistic basis of improved outcomes cannot be solely explained by caloric restriction. Emerging data suggest that bile acid metabolic pathways, luminal contents, energy balance, gut mucosal integrity, as well as the gut microbiota are significantly modulated after bariatric surgery and may be responsible for the variable outcomes, each of which was rigorously evaluated. The RW served as a timely and novel academic meeting that brought together clinicians and researchers across the scientific spectrum, fostering a unique venue for interdisciplinary collaboration among investigators. It promoted engaging discussion and evolution of new research hypotheses and ideas, driving the development of novel ameliorative, therapeutic, and nonsurgical interventions targeting obesity and its comorbidities. Importantly, a critical evaluation of the current knowledge regarding gut-modulated signaling after bariatric surgery, potential pitfalls, and lacunae were thoroughly addressed.

Habitual physical activity is associated with lower fasting and greater glucose-induced GLP-1 response in men

RATIONALE

The hormone glucagon-like peptide-1 (GLP-1) decreases blood glucose and appetite. Greater physical activity (PA) is associated with lower incidence of type 2 diabetes. While acute exercise may increase glucose-induced response of GLP-1, it is unknown how habitual PA affects GLP-1 secretion. We hypothesised that habitual PA associates with greater glucose-induced GLP-1 responses in overweight individuals.

METHODS

Cross-sectional analysis of habitual PA levels and GLP-1 concentrations in 1326 individuals (mean (s.d.) age 66 (7) years, BMI 27.1 (4.5) kg/m2) from the ADDITION-PRO cohort. Fasting and oral glucose-stimulated GLP-1 responses were measured using validated radioimmunoassay. PA was measured using 7-day combined accelerometry and heart rate monitoring. From this, energy expenditure (PAEE; kJ/kg/day) and fractions of time spent in activity intensities (h/day) were calculated. Cardiorespiratory fitness (CRF; mL O2/kg/min) was calculated using step tests. Age-, BMI- and insulin sensitivity-adjusted associations between PA and GLP-1, stratified by sex, were evaluated by linear regression analysis.

RESULTS

In 703 men, fasting GLP-1 concentrations were 20% lower (95% CI: -33; -3%, P = 0.02) for every hour of moderate-intensity PA performed. Higher CRF and PAEE were associated with 1-2% lower fasting GLP-1 (P = 0.01). For every hour of moderate-intensity PA, the glucose-stimulated GLP-1 response was 16% greater at peak 30 min (1; 33%, P rAUC0-30 = 0.04) and 20% greater at full response (3; 40%, P rAUC0-120 = 0.02). No associations were found in women who performed PA 22 min/day vs 32 min/day for men.

CONCLUSION

Moderate-intensity PA is associated with lower fasting and greater glucose-induced GLP-1 responses in overweight men, possibly contributing to improved glucose and appetite regulation with increased habitual PA.

Impact of XPF rs2276466 polymorphism on cancer susceptibility: a meta-analysis

Association between the xeroderma pigmentosum complementation group F (XPF)rs2276466 located in the excision repair cross complementation group 4 (ERCC4) gene and cancer susceptibility has been widely investigated. However, results thus far have remained controversial. A meta-analysis was performed to identify the impact of this polymorphism on cancer susceptibility. PubMed, Embase and Science-Web databases were searched systematically up to May 20, 2018, to obtain all the records evaluating the association between the rs2276466 polymorphism and the risk of all types of cancers. We used the odds ratio (OR) as a measure of effect, and pooled the data in a Mantel-Haenszel weighed random-effects meta-analysis to provide a summary estimate of the impact of this polymorphism on gastrointestinal cancer, neurogenic cancer and other cancers (breast cancer and SCCHN). All the analyses were carried out in STATA 14.1.11 case–control studies that consisted of 5730 cases and 6756 controls, were eventually included in our meta-analysis. The significant association was observed between the XPFrs2276466 polymorphism and neurogenic cancer susceptibility (recessive model: OR = 1.648, 95% CI = 1.294–2.098, P<0.001). Furthermore, no significant impact of this polymorphism was detected on decreased gastrointestinal cancer risk (dominant model: OR = 1.064, 95%CI = 0.961–1.177, P = 0.233). The rs2276466 polymorphism might play different roles in carcinogenesis of various cancer types. Current evidence did not suggest that this polymorphism was directly associated with gastrointestinal susceptibility. However, this polymorphism might contribute to increased neurogenic cancer risk. More preclinical and epidemiological studies are still imperative for further evaluation

Measurement, Determinants, and Implications of Energy Intake in Athletes

Appropriate energy intake is important for the health and performance of athletes. When an athlete's energy intake is not concordant with energy expenditure, short- and long-term performance can be compromised and negative health effects may arise. The energy intake patterns of athletes are subject to numerous effectors, including exercise response, time, and availability of food. To assess different determinants of energy intake in athletes, we reviewed recent literature regarding the response of appetite-regulating hormones to exercise, appetite perceptions following exercise, chronic exercise-induced adaptations regarding appetite, and social factors regarding energy intake. Additionally, we discussed consequences of aberrant energy intake. The purpose of this review is to clarify understanding about energy intake in athletes and provide insights into methods toward maintaining proper energy intake.

Physiology of energy homeostasis: Models, actors, challenges and the glucoadipostatic loop

The aim of this review is to discuss the physiology of energy homeostasis (EH), which is a debated concept. Thus, we will see that the set-point theory is highly challenged and that other models integrating an anticipative component, such as energy allostasis, seem more relevant to experimental reports and life preservation. Moreover, the current obesity epidemic suggests that EH is poorly efficient in the modern human dietary environment. Non-homeostatic phenomena linked to hedonism and reward seem to profoundly impair EH. In this review, the apparent failed homeostatic responses to energy challenges such as exercise, cafeteria diet, overfeeding and diet-induced weight loss, as well as their putative determinants, are analyzed to highlight the mechanisms of EH. Then, the hormonal, neuronal, and metabolic factors of energy intake or energy expenditure are briefly presented. Last, this review focuses on the contributions of two of the most pivotal and often overlooked determinants of EH: the availability of endogenous energy and the pattern of energy intake. A glucoadipostatic loop model is finally proposed to link energy stored in adipose tissue to EH through changes in eating behavior via leptin and sympathetic nervous system activity.

The type of training program affects appetite-regulating hormones and body weight in overweight sedentary men

Exercise-induced weight loss can occur for several reasons, including changes in circulatory levels of appetite-regulating hormones. The purpose of this study was to compare the effect of various training programs on fasting serum levels of acylated ghrelin, peptide YY 3-36 (PYY3-36) and glucagon-like peptide-1 (GLP-1), as well as weight and body mass index (BMI) changes. Forty-four overweight men were randomly assigned into 4 groups of 11 individuals, which included (i) endurance group (3 sets of 10 min with 80%–90% of maximum heart rate), (ii) resistance group (4 sets of 8 repetitions with 80% of 1-repetition maximum), (iii) concurrent group (combination of programs of endurance and resistance groups in an alternate manner), and (iv) control group. Training protocols were conducted for 12 weeks for 3 sessions per week. Results showed that all 3 types of training programs resulted in weight loss (p = 0.000, p = 0.000, and p = 0.036 for resistance, concurrent, and endurance groups, respectively), BMI reduction (p = 0.000, p = 0.000, and p = 0.034), decreased serum acylated ghrelin (p = 0.000, p = 0.000, and p = 0.004), and increased PYY hormone levels (p = 0.028, p = 0.035, and p = 0.036). However, the effect of resistance training on these changes was more pronounced. Moreover, none of the exercise programs had any effect on serum levels of GLP-1. In addition, there was a significant positive correlation between weight (p = 0.003) and BMI (p = 0.009) changes with ghrelin while a negative correlation was observed between weight (p = 0.003) and BMI (p = 0.03) changes with PYY. The findings suggest that regular exercise training, in particular resistance training, is likely to reduce body weight and improve body composition of overweight inactive people by suppressing orexigenic hormones and stimulating the anorexigenic hormones.

Interindividual Responses of Appetite to Acute Exercise: A Replicated Crossover Study

PURPOSE

Acute exercise transiently suppresses appetite, which coincides with alterations in appetite-regulatory hormone concentrations. Individual variability in these responses is suspected, but replicated trials are needed to quantify them robustly. We examined the reproducibility of appetite and appetite-regulatory hormone responses to acute exercise and quantified the individual differences in responses.

METHODS

Fifteen healthy, recreationally active men completed two control (60-min resting) and two exercise (60-min fasted treadmill running at 70% peak oxygen uptake) conditions in randomized sequences. Perceived appetite and circulating concentrations of acylated ghrelin and total peptide YY (PYY) were measured immediately before and after the interventions. Interindividual differences were explored by correlating the two sets of response differences between exercise and control conditions. Within-participant covariate-adjusted linear mixed models were used to quantify participant-condition interactions.

RESULTS

Compared with control, exercise suppressed mean acylated ghrelin concentrations and appetite perceptions (all ES = 0.62-1.47, P < 0.001) and elevated total PYY concentrations (ES = 1.49, P < 0.001). For all variables, the standard deviation of the change scores was substantially greater in the exercise versus control conditions. Moderate-to-large positive correlations were observed between the two sets of control-adjusted exercise responses for all variables (r = 0.54-0.82, P ≤ 0.036). After adjusting for baseline measurements, participant-condition interactions were present for all variables (P ≤ 0.053).

CONCLUSIONS

Our replicated crossover study allowed, for the first time, the interaction between participant and acute exercise response in appetite parameters to be quantified. Even after adjustment for individual baseline measurements, participants demonstrated individual differences in perceived appetite and hormone responses to acute exercise bouts beyond any random within-subject variability over time.

Effects of active commuting and leisure-time exercise on appetite in individuals with overweight and obesity

Acute exercise is associated with a transient suppression of appetite. The effects of regular exercise on appetite are not well understood. We aimed to determine the effects of active commuting and leisure-time exercise on appetite. One hundred thirty physically inactive women and men (20-45 yr) with overweight and obesity were randomized to 6 mo of habitual lifestyle (CON, n = 18), active commuting (BIKE, n = 35), or leisure-time exercise of moderate [MOD, 50% peak oxygen uptake (V̇o_2peak)-reserve, n = 39] or vigorous (VIG, 70% V̇o_2peak-reserve, n = 38) intensity. Appetite ratings, acylated ghrelin, cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and glucagon were assessed in the basal state and in response to meal and exercise challenges at baseline and 3 and 6 mo. Ad libitum energy intake was determined during test meals. Data from 90 participants (per protocol) were available, and results are comparisons with CON. At 3 mo, ad libitum energy intake was lower in VIG (-22%, P < 0.01), basal glucagon was lower in BIKE ( P < 0.05) and VIG ( P = 0.01), and postprandial ratings of prospective food consumption were lower in MOD ( P = 0.02) and VIG ( P < 0.001). In VIG, ratings of hunger ( P = 0.01) and prospective food consumption ( P = 0.03) were lower after acute exercise at 3 mo. At 6 mo, basal and postprandial GLP-1 were higher ( P ≤ 0.04) whereas postexercise PYY was lower ( P = 0.03) in VIG and postexercise CCK was lower in BIKE ( P = 0.03). Vigorous-intensity exercise training leads to a transient suppression of energy intake and subjective appetite (3 mo) but a more long-term increase in basal and postprandial GLP-1 (6 mo) in individuals with overweight and obesity. NEW & NOTEWORTHY This is the first randomized controlled trial, to our knowledge, investigating long-term effects of exercise domain and intensity on subjective and hormonal markers of appetite and ad libitum energy intake in individuals with overweight and obesity. Appetite was assessed in response to meal and exercise challenges at baseline and at 3 and 6 mo. Anorexigenic effects of exercise vary with the duration of intervention and are restricted to regular leisure-time exercise of vigorous intensity in individuals with overweight and obesity.

Myokine Response to High-Intensity Interval vs. Resistance Exercise: An Individual Approach

Purpose: This study aimed to compare the response to acute exercise of several myokines/hormones involved in metabolic function between two types of training sessions that are growing in popularity for their purported cardiometabolic benefits, high-intensity interval (HIIT) and resistance training (RT). Methods: Seventeen healthy, non-athletic men (23 ± 3 years) participated in this cross-over study. They randomly performed a HIIT [with short (HIIT1) or long (HIIT2) intervals] or a RT session. The concentration of fibroblast-growth factor (FGF) 21, follistatin, ghrelin, interleukin-15, irisin, myostatin, and peptide YY was measured at baseline and 0, 1, 3, 24, 48, and 72 h post-exercise. An individual approach was adopted to determine the rate of responsiveness to each specific cytokine and training mode. Results: A significant condition (session type) by time interaction (p = 0.004) effect was observed for FGF21, with RT eliciting a greater area under the curve (AUC) concentration than HIIT1 (p = 0.02). The AUC for follistatin was significantly greater after HIIT2 compared with RT (p = 0.02). Individual responsiveness to all session types ranged between 19 and 93% depending on the cytokine. However, most subjects (71-100%) responded positively for all cytokines (except for irisin, with only 53% of responders) after 1+ session type. Conclusion: Except for FGF21, our results show no overall differences in the myokine response to HIIT or RT. A considerable individual variability was observed, with some subjects responding to some but not other training session types. Notwithstanding, most responded to at least one training session. Thus, it is mostly the individual response of each subject rather than general recommendations on type of training session (i.e., RT vs. HIIT or HIIT subtypes) that must be taken into consideration for maximizing cardiometabolic benefits in the context of personalized exercise prescription.

Post-Exercise Appetite and Ad Libitum Energy Intake in Response to High-Intensity Interval Training versus Moderate- or Vigorous-Intensity Continuous Training among Physically Inactive Middle-Aged Adults

High-intensity interval training (HIIT) is considered a time-efficient exercise strategy for weight management. However, data regarding the acute appetite and energy intake responses to HIIT versus continuous training remain inconclusive. This study investigated the ad libitum energy intake and appetite responses to a single session of HIIT versus moderate-intensity continuous training (MICT) and vigorous-intensity continuous training (VICT). Using a randomized crossover design, 11 middle-aged physically inactive men (45.7 ± 7.4 years, 23.5 ± 2.1 kg m^-2) participated in three treadmill trials at 7-day intervals. HIIT comprised 10 1-min periods at 100% VO_2max interspersed with 1-min periods of active recovery. MICT comprised a 40-min session at 65% VO_2max, while VICT comprised a 20-min session at 80% VO_2max. After each trial, the participants consumed an ad libitum buffet meal for which the energy intake was recorded. The participants' perceived appetite was assessed before and after exercise sessions using the Visual Analogue Scale (VAS). No significant differences in post-exercise ad libitum energy intake were observed between trials (HIIT: 645 ± 262.9 kcal; MICT: 614.7 ± 271.2 kcal; VICT: 623.1 ± 249.0 kcal, p > 0.05). Although the perceived appetite responses exhibited a significant main effect of time (p < 0.01), no group differences were observed (p > 0.05). In summary, these findings suggest that the interval or continuous nature of exercise has no significant effect on appetite responses in physically inactive middle-aged adults, at least during the short-term post-exercise period.

Dietary intake of professional Australian football athletes surrounding body composition assessment

BACKGROUND

Sports Dietitians aim to assist in improving performance by developing nutrition knowledge (NK), enhancing dietary intake and optimising body composition of athletes. In a high-pressure environment, it is important to identify factors that may compromise an athlete's nutrition status. Body composition assessments are regularly undertaken in sport to provide feedback on training adaptions; however, no research has explored the impact of these assessments on the dietary intake of professional athletes.

METHODS

This cross-sectional study assessed dietary intake (7-day food diary), nutrition knowledge (Nutrition for Sport Knowledge Questionnaire) and body composition (Dual-energy X-ray absorptiometry) of 46 professional male Australian football (AFL) athletes during a 2017 pre-season training week (7 days) where body composition assessments were undertaken. Dietary intake was assessed against International Olympic Committee recommendations for professional athletes.

RESULTS

Overall, no athlete met dietary their recommended energy intake (15 ± 1.1 vs. 9.1 ± 1.8 MJ, respectively) or carbohydrate recommendations (6-10 vs. 2.4 ± 0.9 g·kg-1·day-1). Only 54% met protein recommendations. Secondary analyses demonstrated significant associations between education status and energy intake (P < 0.04) and vegetable intake (P < 0.03), with higher levels of education being associated with higher intakes. A moderately positive association was observed between NK scores and meeting estimated energy requirements (r = 0.33, P = 0.03). NK scores were also positively associated with protein (r = 0.35, P = 0.02), fibre (r = 0.51, P = 0.001) and calcium intakes (r = 0.43, P = 0.004).

CONCLUSIONS

This research identified that the dietary intake of professional AFL athletes during a pre-season training week where body composition assessments were undertaken did not meet current recommendations. Several factors may influence the dietary intake of AFL athletes, including lower education levels, poor NK and dietary intake restriction surrounding body composition assessment. Athletes may require support to continue with performance-based nutrition plans in periods surrounding body composition assessment.

Sarcopenic obesity in older adults: aetiology, epidemiology and treatment strategies

The prevalence of obesity in combination with sarcopenia (the age-related loss of muscle mass and strength or physical function) is increasing in adults aged 65 years and older. A major subset of adults over the age of 65 is now classified as having sarcopenic obesity, a high-risk geriatric syndrome predominantly observed in an ageing population that is at risk of synergistic complications from both sarcopenia and obesity. This Review discusses pathways and mechanisms leading to muscle impairment in older adults with obesity. We explore sex-specific hormonal changes, inflammatory pathways and myocellular mechanisms leading to the development of sarcopenic obesity. We discuss the evolution, controversies and challenges in defining sarcopenic obesity and present current body composition modalities used to assess this condition. Epidemiological surveys form the basis of defining its prevalence and consequences beyond comorbidity and mortality. Current treatment strategies, and the evidence supporting them, are outlined, with a focus on calorie restriction, protein supplementation and aerobic and resistance exercises. We also describe weight loss-induced complications in patients with sarcopenic obesity that are relevant to clinical management. Finally, we review novel and potential future therapies including testosterone, selective androgen receptor modulators, myostatin inhibitors, ghrelin analogues, vitamin K and mesenchymal stem cell therapy.

Acute Effects of High-Intensity Interval and Moderate-Intensity Continuous Exercise on GLP-1, Appetite and Energy Intake in Obese Men: A Crossover Trial

This study investigated the effect of high-intensity interval (HIIE) and moderate-intensity continuous exercise (MICE) on glucagon-like peptide 1 (GLP-1), appetite and energy intake (EI) in obese men. In a randomized crossover trial, 12 participants (28.4 ± 2.6 years, 35.5 ± 4.5 kg/m², 39.8 ± 2.2% body fat) performed: (I) Control (CON, no exercise); (II) MICE (20 min, 70% of maximal heart rate) and (III) HIIE (10 × 1 min at 90% of maximal heart rate with 1 min recovery). GLP-1 and appetite were assessed at: (I) PRE: pre-exercise; (II) POST: immediately post-exercise; (III) POST-1 h: 1 h post-exercise. EI was assessed after an ad libitum meal offered 1 h post-exercise and over 24 h. There was a significant time × condition interaction for GLP-1 (p = 0.035). Higher GLP-1 levels in MICE vs. CON (p = 0.024) and a trend for HIIE vs. CON (p = 0.069) POST-1h was found. Hunger was reduced immediately post-HIIE compared to CON (p < 0.01), but was not sustained POST-1 h (p > 0.05). EI did not differ between the sessions 1 h post-exercise or over 24H (p > 0.05). In summary, although MICE increased GLP-1 levels POST-1h and HIIE induced a transient reduction in hunger, both exercise protocols did not impact EI in obese men.

Intense physical exercise potentiates glucose inhibitory effect over food intake of male Wistar rats

NEW FINDINGS

What is the central question of this study? How does an acute session of exercise affect food intake of male Wistar rats? What is the main finding and its importance? Food intake in male Wistar rats is decreased in the first hour after physical exercise independent of the intensity. Moreover, high-intensity exercise potentiates the anorexic effect of peripheral glucose administration. This work raises new feeding-related targets that would explain how exercise drives body weight loss.

ABSTRACT

Obesity has emerged as a critical metabolic disorder in modern society. An adequate lifestyle with a well-oriented programme of diet and physical exercise (PE) can prevent or potentially even cure obesity. Additionally, PE might lead to weight loss by increasing energy expenditure and decreasing hunger perception. In this article, we hypothesize that an acute exercise session would potentiate the glucose inhibitory effects on food intake in male Wistar rats. Our data show that moderate- or high-intensity PE significantly decreased food intake, although no changes in the expression of feeding-related neuropeptide in the arcuate nucleus of the hypothalamus were found. Exercised animals demonstrated a reduced glucose tolerance and increased blood insulin concentration. Intraperitoneal administration of glucose decreased food intake in control animals. In the animals submitted to moderate-intensity PE, the decrease in food intake promoted by glucose was similar to controls; however, an interaction was observed when glucose was injected in the high-intensity PE group, in which food intake was significantly lower than the effect produced by glucose alone. A different pattern of expression was observed for the monocarboxylate transporter isoforms (MCT1, 2 and 4) and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFBP3) in the hypothalamus, which was dependent on the exercise intensity. In conclusion, PE decreases food intake independently of the intensity. However, an interaction between PE and the anorexic effect of glucose is only observed when a high-intensity exercise is performed. These data show an essential role of exercise intensity in the modulation of the glucose inhibitory effect on food intake.

Aerobic exercise modulates anticipatory reward processing via the μ-opioid receptor system

Physical exercise modulates food reward and helps control body weight. The endogenous µ-opioid receptor (MOR) system is involved in rewarding aspects of both food and physical exercise, yet interaction between endogenous opioid release following exercise and anticipatory food reward remains unresolved. Here we tested whether exercise-induced opioid release correlates with increased anticipatory reward processing in humans. We scanned 24 healthy lean men after rest and after a 1 h session of aerobic exercise with positron emission tomography (PET) using MOR-selective radioligand [¹¹ C]carfentanil. After both PET scans, the subjects underwent a functional magnetic resonance imaging (fMRI) experiment where they viewed pictures of palatable versus nonpalatable foods to trigger anticipatory food reward responses. Exercise-induced changes in MOR binding in key regions of reward circuit (amygdala, thalamus, ventral and dorsal striatum, and orbitofrontal and cingulate cortices) were used to predict the changes in anticipatory reward responses in fMRI. Exercise-induced changes in MOR binding correlated negatively with the exercise-induced changes in neural anticipatory food reward responses in orbitofrontal and cingulate cortices, insula, ventral striatum, amygdala, and thalamus: higher exercise-induced opioid release predicted higher brain responses to palatable versus nonpalatable foods. We conclude that MOR activation following exercise may contribute to the considerable interindividual variation in food craving and consumption after exercise, which might promote compensatory eating and compromise weight control.

Does Habitual Physical Activity Increase the Sensitivity of the Appetite Control System? A Systematic Review

Background

It has been proposed that habitual physical activity improves appetite control; however, the evidence has never been systematically reviewed.

Objective

To examine whether appetite control (e.g. subjective appetite, appetite-related peptides, food intake) differs according to levels of physical activity.

Data Sources

Medline, Embase and SPORTDiscus were searched for articles published between 1996 and 2015, using keywords pertaining to physical activity, appetite, food intake and appetite-related peptides.

Study Selection

Articles were included if they involved healthy non-smoking adults (aged 18–64 years) participating in cross-sectional studies examining appetite control in active and inactive individuals; or before and after exercise training in previously inactive individuals.

Study Appraisal and Synthesis

Of 77 full-text articles assessed, 28 studies (14 cross-sectional; 14 exercise training) met the inclusion criteria.

Results

Appetite sensations and absolute energy intake did not differ consistently across studies. Active individuals had a greater ability to compensate for high-energy preloads through reductions in energy intake, in comparison with inactive controls. When physical activity level was graded across cross-sectional studies (low, medium, high, very high), a significant curvilinear effect on energy intake (z-scores) was observed.

Limitations

Methodological issues existed concerning the small number of studies, lack of objective quantification of food intake, and various definitions used to define active and inactive individuals.

Conclusion

Habitually active individuals showed improved compensation for the energy density of foods, but no consistent differences in appetite or absolute energy intake, in comparison with inactive individuals. This review supports a J-shaped relationship between physical activity level and energy intake. Further studies are required to confirm these findings.

PROSPERO Registration Number

CRD42015019696

Electronic supplementary material

The online version of this article (doi:10.1007/s40279-016-0518-9) contains supplementary material, which is available to authorized users.

EFFECTS OF DIFFERENT VOLUMES OF RESISTANCE EXERCISE ON THE FOOD INTAKE OF RATS

ABSTRACT Introduction: Physical exercise changes food intake after an acute session; however further research is needed to identify the effects of resistance exercise (RE) with different training volumes. Objective: To investigate the effects of acute RE (two sessions) with different training volumes on the food intake of rats. Methods: Twenty four Wistar rats were randomly divided into three groups: control group (who did not perform RE; n=8); RE (stair climbing) with four series (G4, n=8) and overload of 50%, 75%, 90%, and 100% of the maximum load capacity of the animal and RE with eight series (G8; n=8) with two increases of each overload of 50%, 75%, 90%, and 100% of the maximum load capacity of the animal. The average amount of ingested feed was measured for each experimental group 24 and 48 hours after the first RE session and 72 hours after the second RE session. Results: The food intake of the groups that performed the RE session was significantly lower (p<0.05) when compared to the control group only at 24 hours after the first training session. After the second training session (72 h), the G8 showed a significantly lower food intake (p<0.05) when compared to G4 and the control group. However, the food consumption relative to the body mass of the animals (g/gBM) was significantly lower only after the second training session (72 h) in G8 (p<0.05) compared to G4 and the control group. Conclusion: Therefore, the resistance exercise decreases the food intake of rats after an acute session; in addition, a higher training volume seems to be more advantageous. Level of Evidence II; Therapeutic studies - Investigation of treatment results.

The Chronic Effect of Interval Training on Energy Intake: A Systematic Review and Meta-Analysis

Single bouts of acute exercise do not appear to increase subsequent energy intake (EI), even when energy deficit is large. However, studies have shown a compensatory effect on EI following chronic exercise, and it remains unclear whether this is affected by exercise intensity. We investigated the chronic effect of high-intensity interval training (HIIT) and sprint interval training (SIT) on EI when compared with moderate-intensity continuous training (MICT) or no exercise (CON). Databases were searched until 13 March 2017 for studies measuring EI in response to chronic exercise (≥4 weeks of duration) of a high-intensity interval nature. Meta-analysis was conducted for between-group comparisons on EI (kilojoules) and bodyweight (kg). Results showed large heterogeneity, and therefore, metaregression analyses were conducted. There were no significant differences in EI between HIIT/SIT versus MICT (P=0.282), HIIT/SIT versus CON (P=0.398), or MICT versus CON (P=0.329). Although bodyweight was significantly reduced after HIIT/SIT versus CON but not HIIT/SIT versus MICT (in studies measuring EI), this was not clinically meaningful (<2% mean difference). In conclusion, there is no compensatory increase in EI following a period of HIIT/SIT compared to MICT or no exercise. However, this review highlights important methodological considerations for future studies.

Physical Exercise in Major Depression: Reducing the Mortality Gap While Improving Clinical Outcomes

Major depression shortens life while the effectiveness of frontline treatments remains modest. Exercise has been shown to be effective both in reducing mortality and in treating symptoms of major depression, but it is still underutilized in clinical practice, possibly due to prevalent misperceptions. For instance, a common misperception is that exercise is beneficial for depression mostly because of its positive effects on the body ("from the neck down"), whereas its effectiveness in treating core features of depression ("from the neck up") is underappreciated. Other long-held misperceptions are that patients suffering from depression will not engage in exercise even if physicians prescribe it, and that only vigorous exercise is effective. Lastly, a false assumption is that exercise may be more harmful than beneficial in old age, and therefore should only be recommended to younger patients. This narrative review summarizes relevant literature to address the aforementioned misperceptions and to provide practical recommendations for prescribing exercise to individuals with major depression.

Anxiety, Depression, and the Microbiome: A Role for Gut Peptides

The complex bidirectional communication between the gut and the brain is finely orchestrated by different systems, including the endocrine, immune, autonomic, and enteric nervous systems. Moreover, increasing evidence supports the role of the microbiome and microbiota-derived molecules in regulating such interactions; however, the mechanisms underpinning such effects are only beginning to be resolved. Microbiota-gut peptide interactions are poised to be of great significance in the regulation of gut-brain signaling. Given the emerging role of the gut-brain axis in a variety of brain disorders, such as anxiety and depression, it is important to understand the contribution of bidirectional interactions between peptide hormones released from the gut and intestinal bacteria in the context of this axis. Indeed, the gastrointestinal tract is the largest endocrine organ in mammals, secreting dozens of different signaling molecules, including peptides. Gut peptides in the systemic circulation can bind cognate receptors on immune cells and vagus nerve terminals thereby enabling indirect gut-brain communication. Gut peptide concentrations are not only modulated by enteric microbiota signals, but also vary according to the composition of the intestinal microbiota. In this review, we will discuss the gut microbiota as a regulator of anxiety and depression, and explore the role of gut-derived peptides as signaling molecules in microbiome-gut-brain communication. Here, we summarize the potential interactions of the microbiota with gut hormones and endocrine peptides, including neuropeptide Y, peptide YY, pancreatic polypeptide, cholecystokinin, glucagon-like peptide, corticotropin-releasing factor, oxytocin, and ghrelin in microbiome-to-brain signaling. Together, gut peptides are important regulators of microbiota-gut-brain signaling in health and stress-related psychiatric illnesses.

Effects of walking in water on gut hormone concentrations and appetite: comparison with walking on land

The effects of water exercise on gut hormone concentrations and appetite currently remain unclear. The aim of the present study was to investigate the effects of treadmill walking in water on gut hormone concentrations and appetite. Thirteen men (mean ± s.d. age: 21.6 ± 2.2 years, body mass index: 22.7 ± 2.8 kg/m², peak oxygen uptake (VO_2peak): 49.8 ± 7.8 mL/kg per min) participated in the walking in water and on land challenge. During the study period, ratings of subjective feelings of hunger, fullness, satiety and motivation to eat were reported on a 100-mm visual analog scale. A test meal was presented after walking, and energy intake (EI) was calculated. Blood samples were obtained during both trials to measure glucagon-like peptide-1 (GLP-1), peptide YY (PYY) and acylated ghrelin (AG) concentrations. Hunger scores (How hungry do you feel?) were significantly lower during the water trial than during the land trial (P < 0.05). No significant differences were observed in EI between water and land trials. GLP-1 concentrations were significantly higher in the water trial than in the land trial (P < 0.05). No significant differences were observed in PYY concentrations between water and land trials. AG concentrations were significantly lower in the water trial than in the land trial (P < 0.01). In conclusion, changes in gut hormone concentrations during walking in water contribute to the exercise-induced suppression of appetite and provide novel information on the influence of walking in water on the acute regulation of appetite.