Effect of exercise training before and after bariatric surgery: A systematic review and meta-analysis.

We aimed to assess the effectiveness of exercise training programs in adults with severe obesity undergoing bariatric surgery. A systematic search of controlled trials published up to October 2019 that assigned participants to either a preoperative or postoperative exercise training group or a nonexercise group was performed. Meta-analyses were conducted using random-effects models. Twenty-two training programs were assessed (18 performed after bariatric surgery). The effect of preoperative exercise training on postsurgery outcomes was reported in only one study. Compared with the control condition without exercise, postoperative exercise training led to higher weight loss (N = 14, mean difference [95% CI] = -1.8 [-3.2; -0.4] kg, P = 0.01), fat loss (N = 9, P = 0.01), increase in VO2 max (N = 8, P < 0.0001), and increase in muscle strength (N = 9, P < 0.0001). No significant effect was found on lean body mass (N = 11). Preliminary evidence suggests a beneficial effect of postoperative exercise training on bone mineral density (N = 3, P < 0.001) and weight maintenance after the end of the intervention (N = 2, P < 0.001) but no significant effect on quality of life (N = 2), habitual physical activity (N = 2), or cardiometabolic outcomes (N < 4). In conclusion, exercise training performed after bariatric surgery improves physical fitness and leads to a small additional weight and fat loss and may prevent bone loss and weight regain after bariatric surgery.

Exercise training in the management of overweight and obesity in adults: Synthesis of the evidence and recommendations from the European Association for the Study of Obesity Physical Activity Working Group.

There is a need for updated practice recommendations on exercise in the management of overweight and obesity in adults. We summarize the evidence provided by a series of seven systematic literature reviews performed by a group of experts from across Europe. The following recommendations with highest strength (Grade A) were derived. For loss in body weight, total fat, visceral fat, intra-hepatic fat, and for improvement in blood pressure, an exercise training program based on aerobic exercise at moderate intensity is preferentially advised. Expected weight loss is however on average not more than 2 to 3 kg. For preservation of lean mass during weight loss, an exercise training program based on resistance training at moderate-to-high intensity is advised. For improvement in insulin sensitivity and for increasing cardiorespiratory fitness, any type of exercise training (aerobic, resistance, and combined aerobic or resistance) or high-intensity interval training (after thorough assessment of cardiovascular risk and under supervision) can be advised. For increasing muscular fitness, an exercise training program based preferentially on resistance training alone or combined with aerobic training is advised. Other recommendations deal with the beneficial effects of exercise training programs on energy intake and appetite control, bariatric surgery outcomes, and quality of life and psychological outcomes in management of overweight and obesity.

Eating Behavior, Physical Activity and Exercise Training: A Randomized Controlled Trial in Young Healthy Adults.

Regular physical activity (PA) is an important part of the treatment of several medical conditions, including overweight and obesity, in which there may be a weakened appetite control. Eating behaviour traits influence weight control and may be different in active and sedentary subjects. This paper reports the relationships between the time spent in sedentary behaviour and physical activity (PA) of different intensity, and eating behaviour traits in young, healthy adults. Additionally, it reports the results of a six-month-long, randomized, controlled trial to examine the effect of an exercise intervention on eating behaviour traits. A total of 139 young (22.06 ± 2.26 years) healthy adults (68.35% women) with a Body Mass Index (BMI) of 24.95 ± 4.57 kg/m2 were enrolled. Baseline assessments of habitual PA were made using wrist-worn triaxial accelerometers; eating behaviour traits were examined via the self-reported questionnaires: Binge Eating, Three-Factor Eating Questionnaire-R18 and Control of Eating Questionnaire. The subjects were then randomly assigned to one of three groups: control (usual lifestyle), moderate-intensity exercise (aerobic and resistance training 3¨C4 days/week at a heart rate equivalent to 60% of the heart rate reserve (HRres) for the aerobic component, and at 50% of the 1 repetition maximum (RM) for the resistance component), or vigorous-intensity exercise (the same training but at 80% HRres for half of the aerobic training, and 70% RM for the resistance training). At baseline, sedentary behaviour was inversely associated with binge eating (r = -0.181, p < 0.05) and with uncontrolled eating (r = -0.286, p = 0.001). Moderate PA (MPA) was inversely associated with craving control (r = -0.188, p < 0.05). Moderate-to-vigorous PA (MVPA) was directly associated with binge eating (r = 0.302, p < 0.001) and uncontrolled eating (r = 0.346, p < 0.001), and inversely associated with craving control (r = -0.170, p < 0.015). Overall, PA was directly associated with binge eating (r = 0.275, p = 0.001), uncontrolled eating (r = 0.321, p < 0.001) and emotional eating (r = 0.204, p < 0.05). Additionally, only emotional eating was modified by the intervention, increasing in the vigorous-intensity exercise group (p < 0.05). In summary, we observed that time spent in sedentary behaviour/PA of different intensity is associated with eating behaviour traits, especially binge eating in young adults. In contrast, the six-month exercise intervention did not lead to appreciable changes in eating behaviour traits.

Validation of the Activity Preference Assessment: a tool for quantifying children's implicit preferences for sedentary and physical activities.

BACKGROUND: High levels of sedentary behavior and low physical activity are associated with poor health, and the cognitive determinants of these behaviors in children and adolescents are not well understood. To address this gap, we developed a novel, non-verbal, computer-based assessment to quantify the degree to which youth prefer to be sedentary relative to physically active in their leisure time. METHODS: The Activity Preference Assessment (APA) uses a forced-choice paradigm to understand implicit decision-making processes when presented with common sedentary and physical activities. The APA bias score ranges from - 100 to + 100, with positive scores indicating a relative preference for sedentary activities, and negative scores representing a preference for physical activities. In 60 children ages 8-17 years, we assessed the validity of this behavioral task against a free-choice play observation, accelerometry-measured activity, anthropometrics and body composition, and cardiorespiratory fitness. We explored neighborhood, family, and individual-level factors that may influence implicit activity preferences. Test-retest reliability was assessed over one week. RESULTS: The majority of children (67%) preferred sedentary relative to physical activities. APA bias scores were positively associated with sedentary time during free-choice play. In girls, bias scores were negatively associated with average daily MVPA. APA bias scores were positively associated with body fat and negatively associated with cardiorespiratory fitness. These findings were independent of age, sex, and race/ethnicity. Neighborhood access to physical activity spaces, the number of people in the home, perceived physical self-competence (e.g., coordination, strength), and self-reported depressive symptoms were associated with activity preferences. The intra-class correlation for test-retest reliability was r = 0.59. CONCLUSIONS: The APA shows promise as a novel tool for quantifying children's relative preference for sedentary versus physical activities. Implicit bias scores from the APA are clinically meaningful, as shown by significant associations with adiposity and cardiorespiratory fitness. Future longitudinal studies should examine the directionality of the association between preferences and health markers, and the degree to which implicit activity preferences are modifiable. Importantly, the task only takes an average of 10 min to complete, highlighting a potential role as an efficient screening tool for the propensity to be sedentary versus physically active. TRIAL REGISTRATION: ClinicalTrials.gov NCT03624582 .

Issues in Measuring and Interpreting Human Appetite (Satiety/Satiation) and Its Contribution to Obesity.

PURPOSE OF REVIEW: The goals of this paper are to report current research practices in investigations of human appetite control and to assess their relationships with emerging theoretical principles. Appetite is often distinguished by the separation of homeostatic and hedonic processes. RECENT FINDINGS: This report assesses the validity of a homeostatic toolkit to measure subjectively perceived hunger and its relationship to the developing processes of satiation (control of meal size) and satiety (control of the post-eating period). The capacity of a procedure to measure the influence of hedonic processes on food intake is also evaluated. A major issue is the relationship between the pattern of eating behaviour (influenced by the underlying drive to eat and the inhibition induced by the act of eating itself) and the parallel underlying profile of hormonal and other metabolic biomarkers. Increasing recognition is being given to individual variability in the expression of appetite, and the fact that the use of the average (mean) response conceals important information about the nature of appetite control. There is a growing interest in the identification of satiety phenotypes that operate in parallel to metabolic phenotypes. Interestingly, energy expenditure (metabolic and behavioural) contributes to an energy balance framework for understanding energy intake (appetite).

Biological control of appetite: A daunting complexity.

OBJECTIVE: This review summarizes a portion of the discussions of an NIH Workshop (Bethesda, MD, 2015) titled "Self-Regulation of Appetite-It's Complicated," which focused on the biological aspects of appetite regulation. METHODS: This review summarizes the key biological inputs of appetite regulation and their implications for body weight regulation. RESULTS: These discussions offer an update of the long-held, rigid perspective of an "adipocentric" biological control, taking a broader view that also includes important inputs from the digestive tract, from lean mass, and from the chemical sensory systems underlying taste and smell. It is only beginning to be understood how these biological systems are integrated and how this integrated input influences appetite and food eating behaviors. The relevance of these biological inputs was discussed primarily in the context of obesity and the problem of weight regain, touching on topics related to the biological predisposition for obesity and the impact that obesity treatments (dieting, exercise, bariatric surgery, etc.) might have on appetite and weight loss maintenance. Finally considered is a common theme that pervaded the workshop discussions, which was individual variability. CONCLUSIONS: It is this individual variability in the predisposition for obesity and in the biological response to weight loss that makes the biological component of appetite regulation so complicated. When this individual biological variability is placed in the context of the diverse environmental and behavioral pressures that also influence food eating behaviors, it is easy to appreciate the daunting complexities that arise with the self-regulation of appetite.

Low levels of physical activity are associated with dysregulation of energy intake and fat mass gain over 1 year.

BACKGROUND: Previous studies suggest that appetite may be dysregulated at low levels of activity, creating an energy imbalance that results in weight gain. OBJECTIVE: The aim was to examine the relation between energy intake, physical activity, appetite, and weight gain during a 1-y follow-up period in a large sample of adults. DESIGN: Participants included 421 individuals (mean ± SD age: 27.6 ± 3.8 y). Measurements included the following: energy intake with the use of interviewer-administered dietary recalls and calculated by using changes in body composition and energy expenditure, moderate-to-vigorous physical activity (MVPA) with the use of an arm-based monitor, body composition with the use of dual-energy X-ray absorptiometry, and questionnaire-derived perceptions of dietary restraint, disinhibition, hunger, and control of eating. Participants were grouped at baseline into quintiles of MVPA (min/d) by sex. Measurements were repeated every 3 mo for 1 y. RESULTS: At baseline, an inverse relation existed between body weight and activity groups, with the least-active group (15.7 ± 9.9 min MVPA/d, 6062 ± 1778 steps/d) having the highest body weight (86.3 ± 13.2 kg) and the most-active group (174.5 ± 60.5 min MVPA/d, 10260 ± 3087 steps/d) having the lowest body weight (67.5 ± 11.0 kg). A positive relation was observed between calculated energy intake and activity group, except in the lowest quintile of activity. The lowest physical activity group reported higher levels of disinhibition (P = 0.07) and cravings for savory foods (P = 0.03) compared with the group with the highest level of physical activity. Over 1 y of follow-up, the lowest activity group gained the largest amount of fat mass (1.7 ± 0.3 kg) after adjustment for change in MVPA and baseline fat mass. The odds of gaining >3% of fat mass were between 1.8 and 3.8 times as high for individuals in the least-active group as for those in the middle activity group. CONCLUSIONS: These results suggest that low levels of physical activity are a risk factor for fat mass gain. In the current sample, a threshold for achieving energy balance occurred at an activity level corresponding to 7116 steps/d, an amount achievable by most adults. This trial was registered at clinicaltrials.gov as NCT01746186.

Effect of chronic exercise on appetite control in overweight and obese individuals.

PURPOSE: The effect of exercise on body mass is likely to be partially mediated through changes in appetite control. However, no studies have examined the effect of chronic exercise on obestatin and cholecystokinin (CCK) plasma concentrations or the sensitivity to detect differences in preload energy in obese individuals. The objective of this study was to investigate the effects of chronic exercise on 1) fasting and postprandial plasma concentrations of obestatin, CCK, leptin, and glucose insulinotropic peptide (GIP) and 2) the accuracy of energy compensation in response to covert preload manipulation. METHODS: This study used a 12-wk supervised exercise program in 22 sedentary overweight/obese individuals. Fasting/postprandial plasma concentrations of obestatin, CCK, leptin, and GIP were assessed before and after the intervention. Energy compensation at a 30-min test meal after a high-energy (607 kcal) or a low-energy (246 kcal) preload and for the rest of the day (cumulative energy intake [EI]) was also measured. RESULTS: There was a significant reduction in the plasma concentration of fasting plasma GIP and both fasting and postprandial leptin concentrations after the exercise intervention (P < 0.05 for all). No significant changes were observed for CCK or obestatin. A significant preload-exercise interaction (P = 0.011) was observed on cumulative EI and energy compensation for the same period (-87% ± 196% vs 68% ± 165%, P = 0.011). Weight loss (3.5 ± 1.4 kg, P < 0.0001) was not correlated with changes in energy compensation. CONCLUSIONS: This study suggests that exercise improves the accuracy of compensation for previous EI, independent of weight loss. Unexpectedly, and in contrast to GIP and leptin, exercise-induced weight loss had no effect on obestatin or CCK concentrations.

Relationships among tonic and episodic aspects of motivation to eat, gut peptides, and weight before and after bariatric surgery.

BACKGROUND: The interaction between motivation to eat, eating behavior traits, and gut peptides after Roux-en-Y gastric bypass (RYGB) surgery is not fully understood. METHODS: Appetite and hormone responses to a fixed liquid preload were assessed in 12 obese (body mass index 45 ± 1.9 kg/m(2)) participants immediately before and 3 days, 2 months, and 1 year after RYGB surgery. Subjective appetite and plasma levels of ghrelin, leptin, insulin, and glucagon-like peptide-1 (GLP-1) were measured for a 3-hour postprandial period. Eating behavior traits were also measured using the Three Factor Eating Questionnaire 18 (TFEQR18). RESULTS: There was a decrease in TFEQR18 emotional eating (EE) and uncontrolled eating (UE) from presurgery to 1 year postsurgery but no significant change in cognitive restraint (CR). These changes occurred independently of change in weight. In addition, there was a reduction in subjective appetite ratings and alterations in appetite peptides favoring an anorectic response. Presurgery EE was significantly related to fasting and area under the curve (AUC) ghrelin; UE was associated with AUC desire to eat, and there was a significant association between fasting desire to eat and ghrelin (fasting and AUC). One year postsurgery, UE was positively related to fasting insulin, and CR was negatively associated with GLP-1. UE and subjective hunger were positively correlated, while the relationship between desire to eat and ghrelin remained. CONCLUSION: The relationships among subjective appetite ratings, eating behavior traits, and appetite peptides in obese patients both before and at 1 year after RYGB surgery may contribute to the reduction in a propensity to overeat (as measured by TFEQR18 factors) and weight loss.

Susceptibility to overeating affects the impact of savory or sweet drinks on satiation, reward, and food intake in nonobese women.

Taste is involved in food preference and choice, and it is thought that it can modulate appetite and food intake. The present study investigated the effect of savory or sweet taste on satiation, reward, and food intake and according to individual differences in eating behavior traits underlying susceptibility to overeating. In a crossover design, 30 women (BMI = 22.7 ± 2.3; age = 21.9 ± 2.6 y) consumed a fixed energy preload (360 kJ/g) with a savory, sweet, or bland taste before selecting and consuming items from a test meal ad libitum. Sensations of hunger were used to calculate the satiating efficiency of the preloads. A computerized task was used to examine effects on food reward (explicit liking and implicit wanting). The Three Factor Eating Questionnaire was used to compare individual differences in eating behavior traits. Satiation and total food intake did not differ according to preload taste, but there was an effect on explicit liking and food selection. The savory preload reduced liking and intake of high-fat savory foods compared to sweet or bland preloads. The eating behavior trait disinhibition interacted with preload taste to determine test meal intake. Higher scores were associated with increased food intake after the sweet preload compared to the savory preload. Independent of preload taste, disinhibition was associated with lower satiating efficiency of the preloads and enhanced implicit wanting for high-fat sweet food. Savory taste has a stronger modulating effect on food preference than sweet or bland taste and may help to preserve normal appetite regulation in people who are susceptible to overeating.

Implicit wanting and explicit liking are markers for trait binge eating. A susceptible phenotype for overeating.

The present study used a measure of trait binge eating (Binge Eating Scale; BES) to examine its association with behavioural markers of appetite and food reward. Non-obese female participants consumed a preload before freely selecting and consuming from a test meal. Subjective hunger and hedonic measures of explicit liking and implicit wanting for food were obtained. Food selection and intake of the test meal were measured. Findings were compared according to individual differences in trait binge eating. BES scores correlated with BMI, food intake and selection of high fat sweet foods in the test meal. Comparison of BES scores revealed that higher scores were associated with weaker suppression of hunger after the preload, greater explicit liking for food generally, and increased implicit wanting for high fat sweet food. Trait binge eating is functional at low levels and implicit wanting measured simultaneously with explicit liking may be useful markers for reward-driven overconsumption in this susceptible phenotype.

Pramlintide treatment reduces 24-h caloric intake and meal sizes and improves control of eating in obese subjects: a 6-wk translational research study.

Evidence from rodent studies indicates that the beta-cell-derived neurohormone amylin exerts multiple effects on eating behavior, including reductions in meal size, intake of highly palatable foods, and stress-induced sucrose consumption. To assess the effect of amylin agonism on human eating behavior we conducted a randomized, blinded, placebo-controlled, multicenter study investigating the effects of the amylin analog pramlintide on body weight, 24-h caloric intake, portion sizes, "fast food" intake, and perceived control of eating in 88 obese subjects. After a 2-day placebo lead-in, subjects self-administered pramlintide (180 microg) or placebo by subcutaneous injection 15 min before meals for 6 wk without concomitant lifestyle modifications. Compared with placebo, pramlintide treatment elicited significant mean reductions from baseline in body weight on day 44 (-2.1 +/- 0.3 vs. +0.1 +/- 0.4%, P < 0.001), 24-h caloric intake (-990 +/- 94 vs. -243 +/- 126 kcal on day 3, P < 0.0001; -680 +/- 86 vs. -191 +/- 161 kcal on day 43, P < 0.01), portion sizes, and caloric intake at a "fast food challenge" (-385 +/- 61 vs. -109 +/- 88 kcal on day 44, P < 0.05). Pramlintide treatment also improved perceived control of eating, as demonstrated by a 45% placebo-corrected reduction in binge eating scores (P < 0.01). The results of this translational research study confirm in humans various preclinical effects of amylin agonism, demonstrating that pramlintide-mediated weight loss in obese subjects is accompanied by sustained reductions in 24-h food intake, portion sizes, fast food intake, and binge eating tendencies.

Perspective on the central control of appetite.

Within the last 10 to 15 years, a number of discoveries have revised the way in which scientists view the role of the brain in the control of food intake (1). One aspect of the brain's influence is often characterized as the control of energy homeostasis. This term accounts for a number of factors arising from experimental studies on molecules and food consumption but seems to stop well short of explaining how brain processes articulate the variety of patterns of human feeding. It should be kept in mind that eating is 100% behavior, and this activity links the internal world of molecules and physiological processes with the external world of physical and cultural systems. It is not always clear the extent to which human eating patterns are a function of physiological or environmental pressure; this is, of course,the subject of extensive experimental study and debate. Because much of the current scientific activity on neural control of feeding is driven by the need to understand (and deal with) the causes of obesity, it will be necessary, at some stage, to reconcile the effects of the physiological mechanism believed to be responsible for eating control in the obese with the actual patterns of eating displayed (eating phenotypes) by obese people. Ultimately, the mechanisms and the behavioral phenotypes must match up. Initially, it is useful to consider which components of energy homeostasis are codified in specific molecular processes and neural pathways and to describe how the integration of diverse signaling systems (the codification) is translated into the expression of behavior and the accompanying subjective sensations.

A decrease in physical activity affects appetite, energy, and nutrient balance in lean men feeding ad libitum.

BACKGROUND: It is not clear how decreased activity quantitatively affects energy balance (EB) in subjects feeding ad libitum. OBJECTIVE: We assessed the effect of an imposed sedentary routine on appetite, energy intake (EI), EB, and nutrient balance in lean men for 7 d. DESIGN: Six men with a mean (+/-SD) age of 23.0 +/- 2.3 y, weight of 69.2 +/- 11.4 kg, and height of 1.76 +/- 0.07 m were each studied twice during a sedentary [1.4 x resting metabolic rate (RMR)] and a moderately active (1.8 x RMR) regimen. During each treatment, they resided in the whole-body indirect calorimeter for the 7 d and had ad libitum access to a medium-fat diet of constant, measurable composition. Meal size, frequency, and composition were continually monitored. Motivation to eat was recorded during waking hours. Subjects were weighed in light clothing each morning, and their weight was corrected to nude. RESULTS: Energy expenditure was 9.7 and 12.8 MJ/d [P < 0.01; SE of the difference between means (SED) = 0.41] during the sedentary and active regimens, respectively. EI was 13.5 and 14.4 MJ/d (P = 0.463, SED = 1.06), respectively. There was no regimen effect on hunger, appetite, or body weight. By day 7, cumulative EB was 26.3 and 11.1 MJ, respectively. CONCLUSIONS: Reducing a level of physical activity from 1.8 to 1.4 x RMR can markedly affect EB. A sedentary routine does not induce a compensatory reduction of EI and leads to a significantly positive EB, most of which is stored as fat.