Satiety responsiveness but not food reward is modified in response to an acute bout of low versus high intensity exercise in healthy adults.

To compare the effect of iso-caloric low and high intensity exercises on Satiety Quotient and Food Reward in response to a fixed meal in healthy young adults. Anthropometric measurements, body composition (BIA), aerobic capacity (VO2 max) and food preferences were assessed in 19 healthy normal-weight young adults (21 ±â€¯0.5 years old, 10 men). They randomly completed 3 experimental sessions: i) control session without exercise (CON); ii) High Intensity exercise session (HIE); iii) Low intensity exercise session (LIE). Thirty minutes after exercise or rest, then received a fixed lunch. Food reward (Leeds Food Preference Questionnaire) was assessed before and after the meal. Appetite sensations were assessed at regular intervals, SQ was calculated from the lunch meal and self-reported food intake was collected for the rest of the day. Mean body weight was 66.7 ±â€¯9.2 kg, body mass index was 22.3 ±â€¯2.9 kg/m2 and FM% was 18.7 ±â€¯6.8%. Appetite feelings did not differ between conditions and were not affected by exercise. SQ for satiety was not different between conditions. SQ hunger on CON was significantly higher than on LIE and HIE (p ≤ 0.05) with no difference between exercise conditions. SQ for desire to eat was significantly higher on CON versus HIE (p ≤ 0.01) with no differences between CON and LIE and between exercise sessions. SQ PFC was significantly lower on HIE compared with CON (p = 0.02) with no differences between LIE and CON and between LIE and HIE. Food reward was not significantly different between the three condition as well as self-reported total food and macronutrient intake for the rest of the days. Acute exercise, depending on its intensity, might affect the satiating response to food intake in healthy adults, without altering food reward.

Early improvement in food cravings are associated with long-term weight loss success in a large clinical sample.

This corrects the article DOI: 10.1038/ijo.2017.89.

Early improvement in food cravings are associated with long-term weight loss success in a large clinical sample.

BACKGROUND: Food cravings are associated with dysregulated eating behaviour and obesity, and may impede successful weight loss attempts. Gaining control over food craving is therefore a component in the management of obesity. The current paper examined whether early changes in control over food craving (assessed using the Craving Control subscale on the Control of Eating Questionnaire (CoEQ)) was predictive of weight loss in four phase 3 clinical trials investigating a sustained-release combination of naltrexone/bupropion (NB) in obese adults. The underlying component structure of the CoEQ was also examined. METHOD: In an integrated analysis of four 56-week phase 3 clinical trials, subjects completed the CoEQ and had their body weight measured at baseline and at weeks 8, 16, 28 and 56. All analyses were conducted on subjects who had complete weight and CoEQ measurements at baseline and week 56, and had completed 56 weeks of NB (n=1310) or placebo (n=736). A latent growth curve model was used to examine whether early changes in the CoEQ subscales were associated with decreases in weight loss over time. Confirmatory factor analysis (CFA) was used to determine the psychometric properties of the CoEQ. RESULTS: The factor structure of the CoEQ was consistent with previous findings with a four-factor solution being confirmed: Craving Control, Positive Mood, Craving for Sweet and Craving for Savoury with good internal consistency (Cronbach's α=0.72-0.92). Subjects with the greatest improvement in Craving Control at week 8 exhibited a greater weight loss at week 56. CONCLUSIONS: These findings highlight the importance of the experience of food cravings in the treatment of obesity and support the use of the CoEQ as a psychometric tool for the measurement of food cravings in research and the pharmacological management of obesity.

Modelling the associations between fat-free mass, resting metabolic rate and energy intake in the context of total energy balance.

BACKGROUND: The relationship between body composition, energy expenditure and ad libitum energy intake (EI) has rarely been examined under conditions that allow any interplay between these variables to be disclosed. OBJECTIVE: The present study examined the relationships between body composition, energy expenditure and EI under controlled laboratory conditions in which the energy density and macronutrient content of the diet varied freely as a function of food choice. METHODS: Fifty-nine subjects (30 men: mean body mass index=26.7±4.0 kg m(-2); 29 women: mean body mass index=25.4±3.5 kg m(-)(2)) completed a 14-day stay in a residential feeding behaviour suite. During days 1 and 2, subjects consumed a fixed diet designed to maintain energy balance. On days 3-14, food intake was covertly measured in subjects who had ad libitum access to a wide variety of foods typical of their normal diets. Resting metabolic rate (RMR; respiratory exchange), total daily energy expenditure (doubly labelled water) and body composition (total body water estimated from deuterium dilution) were measured on days 3-14. RESULTS: Hierarchical multiple regression indicated that after controlling for age and sex, both fat-free mass (FFM; P<0.001) and RMR (P<0.001) predicted daily EI. However, a mediation model using path analysis indicated that the effect of FFM (and fat mass) on EI was fully mediated by RMR (P<0.001). CONCLUSIONS: These data indicate that RMR is a strong determinant of EI under controlled laboratory conditions where food choice is allowed to freely vary and subjects are close to energy balance. Therefore, the conventional adipocentric model of appetite control should be revised to reflect the influence of RMR.

Acute post-exercise energy and macronutrient intake in lean and obese youth: a systematic review and meta-analysis.

AIM: This review aims to determine if acute exercise affects subsequent energy and macronutrients intake in obese and non-obese children and adolescents. METHODS: Databases were searched between January 2015 and December 2015 for studies reporting energy and/or macronutrients intake immediately after an acute exercise and control condition, in children and adolescents. From the initial 118 references found, 14 were included for subsequent analysis after screening representing 31 acute exercise conditions that varied in intensity, duration and modality. RESULTS: One study found increased energy intake after exercise, seven decreased and 23 revealed no change. The meta-analysis revealed a significant effect of acute exercise on intake in obese but not in lean youth by a mean difference of -0.430 (95% confidence interval=-0.703 to -0.157, P=0.002) displaying low heterogeneity (I2=0.000; Q=5.875; df=9, P=0.752). The analysis showed that intense exercise only reduces intake in obese children (no intensity effect in lean). Unchanged macronutrients intake was reported in nine studies as opposed to three which found modified lipids, protein and/or carbohydrate intake. CONCLUSION: Although acute exercise does not affect energy intake in lean, it appears to reduced food intake in obese youth when intense, without altering the macronutrients composition of the meal.

Psycho-markers of weight loss. The roles of TFEQ Disinhibition and Restraint in exercise-induced weight management.

Eating behaviour traits, namely Disinhibition and Restraint, have the potential to exert an effect on food intake and energy balance. The effectiveness of exercise as a method of weight management could be influenced by these traits. Fifty eight overweight and obese participants completed 12-weeks of supervised exercise. Each participant was prescribed supervised exercise based on an expenditure of 500 kcal/session, 5d/week for 12-weeks. Following 12-weeks of exercise there was a significant reduction in mean body weight (-3.26±3.63 kg), fat mass (FM: -3.26±2.64 kg), BMI (-1.16±1.17 kg/m(2)) and waist circumference (WC: -5.0±3.23 cm). Regression analyses revealed a higher baseline Disinhibition score was associated with a greater reduction in BMI and WC, while Internal Disinhibition was associated with a larger decrease in weight, %FM and WC. Neither baseline Restraint or Hunger were associated with any of the anthropometric markers at baseline or after 12-weeks. Furthermore, after 12-weeks of exercise, a decrease in Disinhibition and increase in Restraint were associated with a greater reduction in WC, whereas only Restraint was associated with a decrease in weight. Post-hoc analysis of the sub-factors revealed a decrease in External Disinhibition and increase in Flexible Restraint were associated with weight loss. However, an increase in Rigid Restraint was associated with a reduction in %FM and WC. These findings suggest that exercise-induced weight loss is more marked in individuals with a high level of Disinhibition. These data demonstrate the important roles that Disinhibition and Restraint play in the relationship between exercise and energy balance.

Exercise, appetite and weight management: understanding the compensatory responses in eating behaviour and how they contribute to variability in exercise-induced weight loss.

Does exercise promote weight loss? One of the key problems with studies assessing the efficacy of exercise as a method of weight management and obesity is that mean data are presented and the individual variability in response is overlooked. Recent data have highlighted the need to demonstrate and characterise the individual variability in response to exercise. Do people who exercise compensate for the increase in energy expenditure via compensatory increases in hunger and food intake? The authors address the physiological, psychological and behavioural factors potentially involved in the relationship between exercise and appetite, and identify the research questions that remain unanswered. A negative consequence of the phenomena of individual variability and compensatory responses has been the focus on those who lose little weight in response to exercise; this has been used unreasonably as evidence to suggest that exercise is a futile method of controlling weight and managing obesity. Most of the evidence suggests that exercise is useful for improving body composition and health. For example, when exercise-induced mean weight loss is <1.0 kg, significant improvements in aerobic capacity (+6.3 ml/kg/min), systolic (-6.00 mm Hg) and diastolic (-3.9 mm Hg) blood pressure, waist circumference (-3.7 cm) and positive mood still occur. However, people will vary in their responses to exercise; understanding and characterising this variability will help tailor weight loss strategies to suit individuals.

Physiology: does gut hormone PYY3-36 decrease food intake in rodents?

Batterham et al. report that the gut peptide hormone PYY3-36 decreases food intake and body-weight gain in rodents, a discovery that has been heralded as potentially offering a new therapy for obesity. However, we have been unable to replicate their results. Although the reasons for this discrepancy remain undetermined, an effective anti-obesity drug ultimately must produce its effects across a range of situations. The fact that the findings of Batterham et al. cannot easily be replicated calls into question the potential value of an anti-obesity approach that is based on administration of PYY3-36.

Interaction between disinhibition and restraint: Implications for body weight and eating disturbance.

An increase in obesity is usually accompanied by an increase in eating disturbances. Susceptibility to these states may arise from different combinations of underlying traits: Three Factor Eating Questionnaire (TFEQ) Restraint and Disinhibition. Two studies were conducted to examine the interaction between these traits; one on-line study (n=351) and one laboratory-based study (n=120). Participants completed a battery of questionnaires and provided self-report measures of body weight and physical activity. A combination of high Disinhibition and high Restraint was associated with a problematic eating behaviour profile (EAT-26), and a higher rate of smoking and alcohol consumption. A combination of high Disinhibition and low Restraint was associated with a higher susceptibility to weight gain and a higher sedentary behaviour. These data show that different combinations of Disinhibition and Restraint are associated with distinct weight and behaviour outcomes.

Lateral hypothalamus: hoarding behavior elicited by electrical stimulation.

Electrical stimulation of those points in the lateral hypothalamic area of the brain that promote feeding, but not of other points, elicited intense hoarding activity in satiated rats, similar to that produced by long-term food deprivation. This result suggests that hoarding of food is organized by a hypothalamic drive mechanism sensitive to the efflects of long-term nutritional depletion.

Night and day: diurnal differences in the behavioural satiety sequence in male rats.

The behavioural satiety sequence (BSS) is an important method for assessing the selectivity of treatment (physiological, pharmacological and/or genetic) effects on food intake in rodents. The concept describes the natural progression from feeding to resting, with the transition between the two a useful biomarker of behavioural satiety. Although treatments can accelerate (anorexigenics) or delay (orexigenics) this transition without disrupting behavioural structure, the detection of such changes depends upon the timing of the transition under control conditions. Fasting and presatiation are known to affect this timing. However, recent observations in our laboratory have suggested that phase of testing (light or dark) might also be an important consideration. The present study therefore directly compared food intake and the BSS in thoroughly habituated male rats maintained either on a normal light cycle and tested during the light phase or on a reversed light cycle and tested during the dark phase. The results show that phase of testing had relatively little impact on food intake or diverse measures of ingestive and non-ingestive behaviour. Although modest differences were detected in locomotion, grooming and scratching (higher in dark phase), by far the largest difference concerned resting behaviour which had both a later onset and a much lower peak level during dark phase testing. Importantly, these behavioural differences delayed the transition between eating and resting. The potential contribution of diurnal differences in rate of eating is discussed as are the implications of these findings for future studies on the neurobiology of feeding behaviour.

Acute compensatory eating following exercise is associated with implicit hedonic wanting for food.

The efficacy of exercise to promote weight loss could potentially be undermined by its influence on explicit or implicit processes of liking and wanting for food which in turn alter food preference. The present study was designed to examine hedonic and homeostatic mechanisms involved in the acute effects of exercise on food intake. 24 healthy female subjects were recruited to take part in two counterbalanced activity sessions; 50 min of high intensity (70% max heart rate) exercise (Ex) or no exercise (NEx). Subjective appetite sensations, explicit and implicit hedonic processes, food preference and energy intake (EI) were measured immediately before and after each activity session and an ad libitum test meal. Two groups of subjects were identified in which exercise exerted different effects on compensatory EI and food preference. After exercise, compensators (C) increased their EI, rated the food to be more palatable, and demonstrated increased implicit wanting. Compensators also showed a preference for high-fat sweet food compared with non-compensators (NC), independent of the exercise intervention. Exercise-induced changes in the hedonic response to food could be an important consideration in the efficacy of using exercise as a means to lose weight. An enhanced implicit wanting for food after exercise may help to explain why some people overcompensate during acute eating episodes. Some individuals could be resistant to the beneficial effects of exercise due to a predisposition to compensate for exercise-induced energy expenditure as a result of implicit changes in food preferences.

Effects of acute low-dose combined treatment with naloxone and AM 251 on food intake, feeding behaviour and weight gain in rats.

Low-dose combinations of naloxone and rimonabant produce additive effects on food intake and feeding behaviour, yet abolish the scratching syndrome typically induced by rimonabant per se. To assess the generality of these findings, we have examined the acute effects of low-dose combinations of naloxone (0.1 mg/kg) and the rimonabant derivative AM 251 (0.5 and 1.0 mg/kg) on food intake, feeding behaviour and weight gain in non-deprived male rats. Although ineffective when given alone, combined treatment with naloxone and 0.5 mg/kg AM 251 significantly and selectively suppressed mash intake and time spent feeding. By itself, 1.0 mg/kg AM 251 failed to alter any measure of feeding behaviour but did reduce food consumption and induce scratching behaviour. Co-administration of naloxone with 1.0 mg/kg AM 251 not only significantly suppressed both food intake and feeding behaviour but also simultaneously attenuated AM 251-induced scratching. This profile mirrors earlier findings with naloxone/rimonabant and is consistent with the reported diversity of opioid-cannabinoid system interactions at a more molecular level. Although further studies are required (e.g. 'neutral' CB1 receptor antagonists), current data constitute further proof of concept regarding the anorectic efficacy, selectivity and added value of low-dose polytherapy with opioid and CB1 receptor antagonists.

Beneficial effects of exercise: shifting the focus from body weight to other markers of health.

BACKGROUND: Exercise is widely promoted as a method of weight management, while the other health benefits are often ignored. The purpose of this study was to examine whether exercise-induced improvements in health are influenced by changes in body weight. METHODS: Fifty-eight sedentary overweight/obese men and women (BMI 31.8 (SD 4.5) kg/m(2)) participated in a 12-week supervised aerobic exercise intervention (70% heart rate max, five times a week, 500 kcal per session). Body composition, anthropometric parameters, aerobic capacity, blood pressure and acute psychological response to exercise were measured at weeks 0 and 12. RESULTS: The mean reduction in body weight was -3.3 (3.63) kg (p<0.01). However, 26 of the 58 participants failed to attain the predicted weight loss estimated from individuals' exercise-induced energy expenditure. Their mean weight loss was only -0.9 (1.8) kg (p<0.01). Despite attaining a lower-than-predicted weight reduction, these individuals experienced significant increases in aerobic capacity (6.3 (6.0) ml/kg/min; p<0.01), and a decreased systolic (-6.00 (11.5) mm Hg; p<0.05) and diastolic blood pressure (-3.9 (5.8) mm Hg; p<0.01), waist circumference (-3.7 (2.7) cm; p<0.01) and resting heart rate (-4.8 (8.9) bpm, p<0.001). In addition, these individuals experienced an acute exercise-induced increase in positive mood. CONCLUSIONS: These data demonstrate that significant and meaningful health benefits can be achieved even in the presence of lower-than-expected exercise-induced weight loss. A less successful reduction in body weight does not undermine the beneficial effects of aerobic exercise. From a public health perspective, exercise should be encouraged and the emphasis on weight loss reduced.

Homeostatic and neurocognitive control of energy intake in response to exercise in pediatric obesity: a psychobiological framework.

While energy intake and energy expenditure have long been studied independently, the alarming progression of obesity has led to a more integrative approach to energy balance considering their potential interactions. Although the available literature concerned with the effect of chronic and acute exercise on energy intake and appetite control in adults is considerable, these questions remain less explored among children and adolescents. Based on the search of four databases (Medline, Embase, PsycINFO and Cochrane Library; articles published until May 2018), the objective of this review is to summarize and discuss the effect of acute and chronic physical exercise on energy intake and appetite control in children and adolescents with obesity, and to identify the physiological and neurocognitive signals and pathways involved. Evidence suggested that acute intensive exercise has the potential to reduce subsequent energy intake in children and adolescents with obesity but not healthy weight, through both peripheral (mainly gastro-peptides) and neurocognitive (neural responses to food cues) pathways. The nutritional responses to chronic physical activity remain less clear and require further consideration, especially from an anti-obesity perspective.

Individual variability following 12 weeks of supervised exercise: identification and characterization of compensation for exercise-induced weight loss.

OBJECTIVE: To identify and characterize the individual variability in compensation for exercise-induced changes in energy expenditure (EE). DESIGN: Twelve-week exercise intervention. SUBJECTS: Thirty-five overweight and obese sedentary men and women (body mass index, 31.8+/-4.1 kg m(-2); age, 39.6+/-11.0 years) were prescribed exercise five times per week for 12 weeks under supervised conditions. MEASUREMENTS: Body weight, body composition, resting metabolic rate (RMR), total daily energy intake (EI) and subjective appetite sensations were measured at weeks 0 and 12. RESULTS: When all subjects' data were pooled, the mean reduction in body weight (3.7+/-3.6 kg) was significant (P<0.0001) and as predicted, which suggested no compensation for the increase in EE. However, further examination revealed a large individual variability in weight change (-14.7 to +1.7 kg). Subjects were identified as compensators (C) or noncompensators (NC) based on their actual weight loss (mean NC=6.3+/-3.2 kg and C=1.5+/- 2.5 kg) relative to their predicted weight loss. C and NC were characterized by their different metabolic and behavioural compensatory responses. Moderate changes in RMR occurred in C (-69.2+/-268.7 kcal day(-1)) and NC (14.2+/-242.7 kcal day(-1)). EI and average daily subjective hunger increased by 268.2+/-455.4 kcal day(-1) and 6.9+/-11.4 mm day(-1) in C, whereas EI decreased by 130+/-485 kcal day(-1) and there was no change in subjective appetite (0.4+/-9.6 mm day(-1)) in NC. CONCLUSION: These results demonstrate that expressing the exercise-induced change in body weight as a group mean conceals the large inter-individual variability in body weight and compensatory responses. Individuals who experience a lower than predicted weight loss are compensating for the increase in EE.

Overconsumption and obesity: peptides and susceptibility to weight gain.

Physiological control of feeding is mediated by tonic and episodic signalling systems. These are sometimes thought of as long-term and short-term control. Tonic signals arise from tissue stores whereas episodic signals oscillate periodically with the consumption of food. These physiological controls are paralleled in the motivation to eat by long-acting enduring traits (such as disinhibition) and by short-acting states (such as hunger). Peptides are usually envisaged to exert an action on appetite control through the modulation of states such as hunger and satiety (fullness). Here we provide evidence that peptides involved in tonic regulation--such as leptin--may express a control over appetite motivation through an effect on traits that confer a constant readiness to eat, whereas episodic peptides such as GLP-1 influence appetite motivation through a state such as hunger. The distinction between tonic and episodic regulation, and between traits and states has implications for understanding overconsumption and the susceptibility to weight gain.

Behaviourally-selective hypophagic effects of naloxone in non-deprived male rats presented with palatable food.

Endogenous opioids have long been implicated in mechanisms of appetite control. A significant strand in the evidence base has been the hypophagic action of broad-spectrum opioid receptor antagonists (such as naloxone) in opiate-naïve animals. However, while much has been learned about sites of action, underlying receptor mechanisms and the role of taste hedonics, surprisingly little is known about the behavioural selectivity of naloxone-induced hypophagia. As such, two experiments employed detailed video analysis to profile the behavioural effects of naloxone (Experiment 1: 1.0-5.0 mg/kg; Experiment 2: 0.01-1.0 mg/kg) in non-deprived male rats during 1 h free-feeding tests with palatable mash. Results confirmed that, at doses > or =1.0 mg/kg, naloxone consistently suppresses food consumption and feeding behaviour but, congruent with its short biological half-life, had no carryover effects on post-treatment weight gain. Crucially, the anorectic doses of naloxone did not alter the time taken to find food or to commence feeding, the time spent feeding in the initial phase of testing, or the rate at which food was consumed. Furthermore, they neither interfered with non-ingestive components of the behavioural repertoire (e.g. locomotion, rearing) nor did they disrupt the normal structure of feeding behaviour (the behavioural satiety sequence, BSS). Rather, the principal effect of naloxone was to produce a shift to the left in (i.e. accelerate) the BSS. Findings are discussed in relation to the role of (mu) opioid receptor mechanisms in taste hedonics and the likelihood of a naloxone-induced reduction in the orosensory reward that would normally accompany/follow the ingestion of palatable food.

Endogenous opioids and cannabinoids: system interactions in the regulation of appetite, grooming and scratching.

Growing evidence suggests substantial crosstalk between endogenous opioid and cannabinoid systems in the regulation of appetite. Not only is cannabinoid-induced hyperphagia abolished by opioid receptor antagonists (and vice versa), but several laboratories have reported supra-additive anorectic responses following co-administration of opioid and CB1 receptor antagonists. In the present study, videoanalysis has been used to characterise the acute effects of sub-anorectic doses of rimonabant (0.25, 0.75 mg/kg) and naloxone (0.1 mg/kg), alone and in combination, on mash intake, ingestive and non-ingestive behaviour, and post-treatment weight gain in male rats. The results confirmed that, when administered alone, none of these treatments significantly altered mash consumption, various measures of feeding behaviour, or weight gain. Although most non-ingestive behaviours were also unaffected, 0.75 mg/kg rimonabant induced compulsive scratching and grooming. However, when naloxone was given in combination with either dose of rimonabant, both food intake and time spent feeding were significantly decreased while the behavioural satiety sequence (BSS) was accelerated. On further analysis, the co-treatment reductions in food intake and feeding behaviour were found to be of an additive rather than supra-additive nature. Intriguingly, the co-administration of naloxone also virtually abolished the compulsive scratching response to the higher dose of rimonabant. Findings are discussed in relation to current views on the molecular bases of opioid-cannabinoid system interactions and the unexpected 'dual' advantage (reduction in appetite plus attenuation of side-effect) of low-dose combinations of opioid and cannabinoid CB1 receptor antagonists.

Potential effects of fat mass and fat-free mass on energy intake in different states of energy balance.

Recently models have attempted to integrate the functional relationships of fat mass (FM) and fat-free mass (FFM) with the control of human energy intake (EI). Cross-sectional evidence suggests that at or close to EB, FFM is positively related to hunger and EI, whereas FM either shows a weak negative or no association with ad libitum EI. Further analysis suggests that the effects of FFM and FM on EI may be mediated by resting metabolic rate (RMR). These studies suggest that energy turnover is associated with EI and the largest determinant of energy requirements in most humans is FFM. During chronic positive EBs both FM and FFM expand (but disproportionately so), increasing energy demands. There is little evidence that an expanding FM exerts strong negative feedback on longer term EI. However, during chronic negative EBs FM, FFM and RMR all decrease but appetite increases. Some studies suggest that proportionate loss of FFM during weight loss predicts subsequent weight regain. Taken together these lines of evidence suggest that changes in the size and functional integrity of FFM may influence appetite and EI. Increases in FFM associated with either weight gain or high levels of exercise may 'pull' EI upwards but energy deficits that decrease FFM may exert a distinct drive on appetite. The current paper discusses how FM and FFM relationships influence appetite regulation, and how size, structure and functional integrity of FFM may drive EI in humans (i) at EB (ii) during positive EB and (iii) during negative EB.