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The efficacy of exercise as a method of weight loss varies from person to person. In some individuals, mechanisms may operate to oppose negative energy balance. Exercise may alter hedonic characteristics of food which could lead to changes in taste and food preferences. It is possible that as part of the compensatory appetite response, processes of food reward are modulated by exercise to preserve energy balance. Twenty-four females (BMI: 19–28kg/m2) were recruited to take part in two experimental sessions, including 50-min high-intensity exercise (Ex) at 70% max HR or no exercise (NEx), separated by one week. A computer task was employed to measure liking (using palatability ratings) and implicit wanting (using forced-choice reaction time) for a range of photographic food stimuli. Sensations of appetite, measures liking and wanting were assessed before and after exercise manipulation and after ad libitum test-meal to measure energy intake (EI). There was large variability in relative EI (EIEx−EINEx). These individual differences broadly fell into one of two groups: where EI was constant across conditions (Mean Δ −63.1kcal±72.1), or where EIEx was increased (Mean Δ 1411.7kcal±221.5). Degree of compensation correlated with %body fat. Increased EIEx was associated with enhanced implicit wanting but not sensations of taste, liking or hunger. Modulation of implicit aspects of food reward may help explain the variable efficacy of exercise as a method of weight loss. [Copyright &y& Elsevier]

Tendency to binge eat is a known risk factor for weight gain and obesity. The present study examined hedonic and homeostatic processes of appetite regulation in normal weight women with a range of binge eating scores. Thirty-five subjects (24.1±1.0 years, BMI: 21.9±0.5kg/m2) completed the Binge Eating Scale (BES), Three-Factor Eating Questionnaire (TFEQ), Food Craving Scale (FCS) and attended two test-meal sessions comprising a fixed preload followed by an ad libitum buffet. Energy intake, food selection, subjective sensations of appetite and hedonic response were measured. Novel procedures to measure food liking, wanting and preference (Finlayson et al. 2007) were employed. BES scores correlated with BMI (p<0.05), TFEQ-disinhibition (p<0.01) and hunger (p<0.01), and FCS items relating to impaired ability to resist cravings (p<0.05) and loss of control over eating (p<0.05). On comparison of low (<7; N=12) and high (>10; N=12) tertile scores on the BES, higher scores were associated with differences in sensory perception, greater preference for high-fat sweet foods (p<0.05), stronger sensations of hunger post-preload (p<0.01), and increased ad libitum intake of high-fat sweet foods (p<0.01). Higher scores were linked to enhanced explicit wanting for food which persisted after consumption of the preloads (p<0.01). No differences in implicit wanting were found. Within a group of young women with normal BMI, BES scores had the capacity to differentiate high and low BMI plus a range of appetite responses related to motivation to eat, food preference and tendency to overconsume. BES scores could be a useful predictor of weight gain and later obesity. MRC(CASE)#G78/8223 in conjunction with NRC, Lausanne; and INAP-G, Paris. [Copyright &y& Elsevier]

Considering the psychological mechanisms that influence eating, we assume that both implicit and explicit processes will operate. This distinction informs the liking vs. wanting issue of food reward. The present study investigated the effect of meal-induced satiation on implicit and explicit processes of liking (L) and wanting (W) by developing a computer-based procedure to measure L and W in hungry and satiated states. Explicit measures were derived from analogue ratings whilst the implicit W measure was derived from RT in a forced-choice procedure, which also identified food preferences. Seventy subjects (21.8±0.9years, BMI: 22.2±0.5kg/m2) completed the computer-task before and immediately following consumption of a savoury test meal. Satiation caused explicit ratings of L and W to decrease in all food categories (p<0.01); but with a more marked decrease for savoury foods compared with sweet foods (p<0.01). Implicit W was increased for sweet categories (p<0.01), but not for savoury. Implicit and explicit measures of L and W dependently correlated with preference for sweet foods. This study provides support that implicit and explicit processes of food reward can be simultaneously measured and dissociated using a test meal. Adjustments in hunger were linked to changes in explicit L and W in a manner consistent with sensory specific satiety, while a relationship between hunger and implicit W was absent. We suggest that implicit W is not systematically downregulated by the physiological consequences of food consumption in the same way as hunger and therefore may be largely independent of homeostatic processes influencing intake. MRC(CASE)#G78/8223 in conjunction with NRC, Lausanne. [Copyright &y& Elsevier]

While an intensity-dependent post-exercise decrease in energy intake (EI) has been described in adolescents with obesity, studies invariably used ad libitum meals , limiting then any conclusions regarding the effect of exercise on post-meal appetitive responses that can be also impacted by the ad libitum nature of the meal. This study analyses appetite and food-reward related responses to a fixed meal after an acute exercise, also exploring the associations between substrate use during exercise and overall daily EI in adolescents with obesity. Thirteen adolescents with obesity (12–16 years, 5 males) randomly complete 2 experimental sessions: (i) a control condition (CON); (ii) a 30-min moderate intensity (65% VO 2peak) cycling condition (EX). Energy expenditure and substrate oxidation were measured during both 30 min of rest (CON) or exercise (EX). Ad libitum EI, macronutrient intake and relative EI were assessed at dinner, subjective appetite sensations taken at regular intervals and food reward measured before and after lunch as well as before dinner. Energy and macronutrient intake did not differ between conditions, as well as appetite feelings. A time effect (p = 0.012) was observed between pre and post meal for choice fat bias in both conditions but was only significant within the CON condition (p = 0.004). CHO oxidation during exercise was found correlated with both EI (r = 0.586, p = 0.045), pre-lunch hunger (r = 0.624, p = 0.030), daily AUC for hunger and DTE (r = 0.788, p = 0.002 and r = 0.695; p = 0.012 respectively). This exploratory study highlights that acute exercise might not affect subsequent appetite responses when using a fixed test meal in adolescents with obesity. [ABSTRACT FROM AUTHOR]

Aquatic exercise has been suggested as a beneficial modality to improve weight loss, cardiorespiratory fitness and quality of life in adolescents with obesity; however, its impact on appetite control in youth remains unknown. The aim of this preliminary study was to examine the effect of an acute aquatic exercise session on energy intake (EI), appetite feelings and food reward in adolescents with obesity. Twelve adolescents with obesity (12–16 years, Tanner stage 3–5, 9 males) randomly completed two conditions: i) control (CON); ii) aquatic exercise session (AQUA). One hour before lunch, the adolescents stayed at rest outside the water in a quiet room for 45 min on CON while they performed a 45-min aquatic exercise session on AQUA. Ad libitum EI and macronutrients were assessed at lunch and dinner, subjective appetite feelings taken at regular intervals, and food reward measured before and after lunch. Paired T-test showed that EI was not different between CON and AQUA at lunch (1333 ± 484 kcal vs 1409 ± 593 kcal; p = 0.162) and dinner (528 ± 218 kcal vs 513 ± 204 kcal; p = 0.206). Total daily ad libitum EI was significantly higher on AQUA (1922 ± 649 kcal) compared with CON (1861 ± 685 kcal; p = 0.044) but accounting for the exercise-induced energy expenditure, relative energy intake did not differ (2263 ± 732 kcal vs 2117 ± 744 kcal, p = 0.304). None of the appetite feelings (hunger, fullness, prospective food consumption and desire to eat) and food reward dimensions were significantly different between conditions. These preliminary and exploratory results suggest that an acute aquatic-exercise session might not induce energy compensatory responses in adolescents with obesity. [ABSTRACT FROM AUTHOR]

The present study manipulated the delay between exercise and test meal to investigate its effect on energy intake, appetite sensations and food reward in adolescents with obesity. Fifteen adolescents with obesity randomly completed 3 experimental sessions: i) rest without exercise (CON); ii) 30 min of exercise 180 min before lunch (EX-180); iii) 30 min of exercise 60 min before lunch (EX-60). Ad libitum energy intake was assessed at lunch and dinner, and food reward (LFPQ) assessed before and after lunch. Appetite sensations were assessed at regular intervals. Absolute energy intake was not different between conditions despite a 14.4% lower intake in EX-60 relative to CON. Lunch relative energy intake (REI: energy intake - exercise-induced energy expenditure) was higher in CON compared with EX-60 (p < 0.001). Lunch fat intake was lower in EX-60 compared with CON (p = 0.01) and EX-180(p = 0.02). Pre-lunch hunger in CON was lower than EX-180 (p = 0.02). Pre-lunch prospective food consumption and desire to eat were lower in CON compared with both exercise conditions (p = 0.001). A significant condition effect was found for explicit liking for high-fat relative to low-fat foods before lunch (p = 0.03) with EX-60 being significantly lower than EX-180 (p = 0.001). The nutritional and food reward adaptations to exercise might be dependent on the timing of exercise, which is of importance to optimize its effect on energy balance in adolescents with obesity. CLINICAL TRIAL REFERENCE: NCT03807609. [ABSTRACT FROM AUTHOR]

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 ± 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 ± 9.2 kg, body mass index was 22.3 ± 2.9 kg/m2 and FM% was 18.7 ± 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. [ABSTRACT FROM AUTHOR]