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

Acute exercise might not affect subsequent appetite responses to a fixed meal in adolescents with obesity: The SMASH exploratory study

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% VO2peak) 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.

Reward for fat and sweet dimensions of food are altered by an acute bout of running in healthy young men

Acute moderate- to high-intensity exercise, primarily aerobic exercise, has been reported to decrease food reward in brain regions via the hedonic pathways and reduce preference for high-energy or high-fat foods. However, studies examining food reward responses to acute exercise have been limited to measuring food reward only after exercise and less frequently before and after exercise. Therefore, the changes in food reward in response to acute exercise remain unclear. This study investigated the effect of acute running on food reward in healthy young men. Fourteen young healthy men (mean ± standard deviation, age; 23 ± 2 years, body mass index; 21 ± 2 kg/m2) completed two trials (i.e., exercise and control) in a randomised, crossover design. Participants performed a 30-min running bout at 70% of maximal oxygen uptake or sitting rest before and after food reward evaluation with a computer-based food choice behaviour task tool. Food reward was assessed for foods varying in fat content and sweet taste, and there were four assessment parameters: explicit liking, explicit wanting, implicit wanting and frequency of choice of each food category (relative preference). Explicit and implicit wanting, and relative preference for high-fat relative to low-fat foods were reduced after the exercise trial compared to the control trial (trial-by-time interaction, all p ≤ 0.02). Implicit wanting and relative preference for sweet relative to savoury foods were increased after the exercise trial compared to the control trial (trial-by-time interaction, all p ≤ 0.003). These findings indicate that moderate-intensity acute running alters the reward bias away from high fat towards low fat foods and away from savoury towards sweet foods in healthy young men.

Postprandial energy metabolism is modulated in response to a low-intensity walking exercise in fasted healthy individuals

Postprandial metabolism is a relevant indicator of overall metabolic health, which can be influenced by a single bout of exercise before food consumption. The present study examined the effects of an acute, fasted, low-intensity exercise on postprandial metabolism and appetite sensations. We hypothesized that exercise would induce an increase in postprandial fat oxidation, associated with better satiety responses. Twenty-two healthy adults (16 females) attended the laboratory twice separated by a minimum of 3 days to perform 2 conditions: (1) a control condition and (2) an exercise condition (EX) with a 30-minute low-intensity walking exercise performed before the breakfast (500-kcal fixed meal). Subjective appetite sensations were assessed before and up to 60 minutes after the meal in regular intervals. Energy expenditure and substrate oxidation were measured until 2 hours after the meal. Energy expenditure and carbohydrate oxidation were higher in the EX condition (condition effect: P < .01). There was no effect of exercise on appetite sensations and overall fat oxidation, but a higher increase in relative and absolute fat oxidation was observed from 15- to 45-minutes postmeal in EX compared with control (time × condition interaction effect: P < .05). In the EX condition only, postprandial satiety was associated positively with postprandial fat oxidation and negatively with carbohydrate oxidation. To conclude, a fasted low-intensity exercise induced an enhancement of postprandial metabolic flexibility through the modulation of fat oxidation. Substrate oxidation appeared to be related to satiety only after exercise, suggesting a specific regulation of appetite induced by exercise.

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

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

Comparing the Effects of Immersed Versus Land-Based High-Intensity Interval Cycling on Energy Intake, Appetite Sensations and Perceived Exertion Among Healthy Men

Immersed exercise has been shown to induce higher energy expenditure and no difference or increase in food intake compared with similar exercise on land. In this study, we compared the effects of acute high-intensity cycling performed on land versus when immersed on subsequent energy intake (EI), appetite sensations and perceived exertion (RPE) in healthy men. Ten participants in a postprandial condition completed three experimental visits in a randomized order: a control condition (CONT); a high-intensity interval cycling exercise performed on land (HIIE-L) and the same exercise while immersed in water (HIIE-A) with a similar targeted heart rate. We observed no difference in energy and macronutrient intake and in area under the curve (AUC) for appetite sensations between sessions. The RPE at the end of HIIE-L was negatively correlated with EI (r=-0.67; p < 0.05), AUC for hunger (r=-0.86, p < 0.01), desire to eat (r=-0.78, p < 0.05) and prospective food consumption (r=-0.86, p < 0.01). Conversely, the RPE at the end of HIIE-L was positively correlated with AUC for fullness (r = 0.76, p < 0.05). No such correlations were observed for HIIE-A. The present study was the first to observe that immersion did not influence EI after HIIE cycling, but immersion blunted the relationship between session RPE and subsequent energy intake and appetite sensations relative to HIIE on land.

A systematic review of the use of the Satiety Quotient

The satiating efficiency of food has been increasingly quantified using the Satiety Quotient (SQ). The SQ integrates both the energy content of food ingested during a meal and the associated change in appetite sensations. This systematic review examines the available evidence regarding its methodological use and clinical utility. A literature search was conducted in six databases considering studies from 1900 to April 2020 that used SQ in adults, adolescents and children. All study designs were included. From the initial 495 references found, fifty-two were included. Of the studies included, thirty-three were acute studies (twenty-nine in adults and four in adolescents) and nineteen were longitudinal studies in adults. A high methodological heterogeneity in the application of the SQ was observed between studies. Five main utilisations of the SQ were identified: its association with (i) energy intake; (ii) anthropometric variables; (iii) energy expenditure/physical activity; (iv) sleep quality and quantity and (v) to classify individuals by their satiety responsiveness (i.e. low and high satiety phenotypes). Altogether, the studies suggest the SQ as an interesting clinical tool regarding the satiety responsiveness to a meal and its changes in responses to weight loss in adults. The SQ might be a reliable clinical indicator in adults when it comes to both obesity prevention and treatment. There is a need for more standardised use of the SQ in addition to further studies to investigate its validity in different contexts and populations, especially among children and adolescents.

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.