Optimal timing of exercise for influencing energy intake in children during school lunch

Children and chrono-exercise: Timing of physical activity on school and weekend days depends on sex and obesity status

Recommendations for physical activity (PA) typically focus on frequency, intensity, duration, and type, but timing (chrono-exercise) is also important. The objective of this study is to describe when children are active on school and weekend days and explore PA timing across sex and body mass index (BMI) categories. 359 children (53% male), aged 9.6 (0.9) y, were categorized as normal weight (≥-1 standard deviations (SD) and <1SD; n = 193), overweight (≥1SD and <2SD; n = 80), or obese (≥2SD; n = 86) using WHO BMIz. Moderate-to-vigorous PA (MVPA) was assessed using ActiGraph LS-7164. The results are described as Mean(SD). ANOVA evaluated MVPA across sexes and BMI categories. Normal weight boys were more active than boys with obesity on school (Δ20.33 min; p < 0.001) and weekend days (Δ15.04 min; p < 0.05). On school days, significant differences existed between 9:00 h-11:00 h and 12:00 h-14:00 h (p < 0.017), while on weekends, smaller differences existed throughout the day. Girls' MVPA was similar across BMI categories, on all days (p > 0.05). On school days, 12:00 h-13:00 h represented the most active hour for all participants (~14% total daily MVPA). Peak weekend MVPA was distributed across multiple hours. Differences in MVPA timing emerged on school-days and weekends. Timing may be important when examining the nuances of MVPA in relation to sex and bodyweight in children.

Effects of Movement Behaviors on Overall Health and Appetite Control: Current Evidence and Perspectives in Children and Adolescents

PURPOSE OF REVIEW

To present the definitions and recommendations for movement behaviors in children and adolescents, including physical activity (PA), sedentary behaviors (SB), and sleep, and to provide an overview regarding their impact on health and obesity outcomes from childhood to adulthood, as well as interactions with appetite control.

RECENT FINDINGS

PA represents a variable proportion of daily energy expenditure and one can be active with high SB or vice versa. Studies have described movements across the whole day on a continuum from sleep to SB to varying intensities of PA. More PA, less SB (e.g., less screen time) and longer sleep are positively associated with indicators of physical health (e.g., lower BMI, adiposity, cardiometabolic risk) and cognitive development (e.g., motor skills, academic achievement). However, less than 10% of children currently meet recommendations for all three movement behaviors. Movement behaviors, adiposity, and related cardiometabolic diseases in childhood track into adolescence and adulthood. Furthermore, low PA/high SB profiles are associated with increased energy intake. Recent studies investigating energy balance regulation showed that desirable movement behavior profiles are associated with better appetite control and improved eating habits. Early identification of behavioral phenotypes and a comprehensive approach addressing all key behaviors that directly affect energy balance will allow for individual strategies to prevent or treat obesity and its comorbidities. Investigating exercise as a potential "corrector" of impaired appetite control offers a promising weight management approach.

Delayed meal timing after exercise is associated with reduced appetite and energy intake in adolescents with obesity

BACKGROUND

While the beneficial effects of exercise on appetite might depend on its timing during the day or relative to a meal, this remains poorly explored in youth.

OBJECTIVES

To examine the importance of meal timing (+30 vs +90 minutes) after performing exercise on energy intake, appetite and food reward in adolescents with obesity.

METHODS

Eighteen adolescents with obesity randomly completed three conditions: (a) lunch (12:00 pm) set 30 minutes after a rest session (11:00 am); (b) lunch (12:00 pm) set 30 minutes after an exercise session (11:00 am)(MEAL-30); (c) lunch (01:00 pm) set 90 minutes after an exercise session (11:00 am)(MEAL-90). Lunch and dinner ad libitum energy intake was assessed, food reward (LFPQ) assessed before and after lunch, and before dinner, appetite sensations were assessed at regular intervals.

RESULTS

Energy intake was lower at MEAL-90 than MEAL-30 and CON at lunch (P < .05 and P < .01, respectively) and lunch + dinner combined (P < .001). A decrease in intake (g) of protein, fat and carbohydrate was observed. Post-exercise hunger was lower on MEAL-90 compared with CON. No condition effects were found at lunch for food reward.

CONCLUSIONS

Delaying the timing of the meal after exercise might help affect energy balance by decreasing ad libitum energy intake without increasing hunger and by improving satiety in adolescents with obesity.

Does exercising before or after a meal affect energy balance in adolescents with obesity?

BACKGROUND AND AIM

Exercise timing has been suggested to affect appetite and energy intake (EI). The aim of this study was to examine the impact of exercising immediately before or after a meal on EI, appetite sensations and food reward (FR) in adolescents with obesity.

METHODS AND RESULTS

Seventeen adolescents with obesity completed 3 experimental sessions (randomized controlled trial): rest + lunch (CON); exercise + lunch (EX-MEAL); lunch + exercise (MEAL-EX). The exercise consisted of cycling 30 min at 65%V̇O_2peak. Outcomes included ad libitum EI (weighed lunch and dinner), FR (Leeds Food Preference Questionnaire at pre- and post-combination of exercise/rest and lunch, and pre-dinner) and appetite sensations (visual analogue scales). EI was not different between conditions. Compared with CON, relative EI at lunch was lower in EX-MEAL and MEAL-EX (p ≤ 0.05) and daily only in MEAL-EX (p < 0.01). Postprandial fullness was higher in EX-MEAL compared to CON. Compared with CON, both EX-MEAL and MEAL-EX attenuated the increase in wanting for sweet food and reduced explicit liking for fat.

CONCLUSIONS

These preliminary results suggest that exercising immediately before or after a meal produce few differences in appetite and have small beneficial effects on overall energy balance in adolescents with obesity, as well as on FR.

CLINICAL TRIALS

NCT03967782.

Appetite control and exercise: Does the timing of exercise play a role?

The prevention and management of chronic diseases, particularly overweight and obesity, relies on multidisciplinary strategies mainly combining dietary approaches with physical activity. Recently, the timing of exercise (time of the day as well as delay/position relative to a meal) has been suggested as an important parameter to consider when prescribing physical activity. Some studies have for instance shown the interest of the timing of exercise on the glycemia, sleep and body composition regulation. However, the impact of exercise-timing on appetite control and energy intake remains unclear. This is why, the present paper questions whether physical exercise, depending on its timing during the day and related to a meal, can affect energy intake, appetite sensations and food reward. Although evidences remain actually limited, exercising during the morning; and particularly close to lunch, might have a better impact on overall energy balance through reduced subsequent energy intake, without leading to compensatory intakes at the following meals. Importantly, dealing with the timing of exercise to optimize energy balance (and affect energy intake and appetite) does not only require to consider its time during the day (morning vs. afternoon or evening), but also and maybe mainly its order/position (pre vs. post) and delay regarding meals. While the actual literature remains limited in this area, the present paper tends to highlight the importance of considering the timing of exercise to optimize our impact on the overall energy balance, and to encourage the elaboration of further studies to better understand and determine the potential effect of this timing of exercise, in order to find the best combination between the different exercise characteristics, intensity, duration, modality, to empower these effects.

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.

Effects of a 12-Week Exercise Intervention on Subsequent Compensatory Behaviors in Adolescent Girls: An Exploratory Study

PURPOSE

Chronic exercise programs can induce adaptive compensatory behavioral responses through increased energy intake (EI) and/or decreased free-living physical activity in adults. These responses can negate the benefits of an exercise-induced energy deficit; however, it is unclear whether young people experience similar responses. This study examined whether exercise-induced compensation occurs in adolescent girls.

METHODS

Twenty-three adolescent girls, heterogeneous for weight status, completed the study. Eleven adolescent girls aged 13 years completed a 12-week supervised exercise intervention (EX). Twelve body size-matched girls comprised the nonexercise control group (CON). Body composition, EI, free-living energy expenditure (EE), and peak oxygen uptake (V˙O2) were measured repeatedly over the intervention.

RESULTS

Laboratory EI (EX: 9027, 9610, and 9243 kJ·d-1 and CON: 9953, 9770, and 10,052 kJ·d-1 at 0, 12, and 18 wk, respectively; effect size [ES] = 0.26, P = .46) and free-living EI (EX: 7288, 6412, and 5273, 4916 kJ·d-1 and CON: 7227, 7128, and 6470, 6337 kJ·d-1 at 0, 6, 12, and 18 wk, respectively; ES ≤ 0.26, P = .90) did not change significantly over time and were similar between groups across the duration of the study. Free-living EE was higher in EX than CON (13,295 vs 12,115 kJ·d-1, ES ≥ 0.88, P ≥ .16), but no significant condition by time interactions were observed (P ≥ .17).

CONCLUSION

The current findings indicate that compensatory changes in EI and EE behaviors did not occur at a group level within a small cohort of adolescent girls. However, analysis at the individual level highlights large interindividual variability in behaviors, which suggests a larger study may be prudent to extend this initial exploratory research.

Understanding the potential contribution of a third "T" to FITT exercise prescription: the case of timing in exercise for obesity and cardiometabolic management in children

Currently, exercise prescription relies heavily on parameters included in the FITT principle: frequency, intensity, time (duration), and type of exercise. In this paper, the benefits of including timing (FITT+T), referring to when exercise is performed in relation to meal-time, is discussed. Current research indicates that timing is outcome-specific. Total energy and lipid intakes, and postprandial hypertriglyceridemia can be reduced when exercise is performed pre-meal, while glycemic control is improved with post-meal exercise. Although findings indicate that timing can aid in obesity management and cardiometabolic-risk reduction, most research involves adult subjects and acute investigations. Some research with children, concerning the effect of timing on appetite, indicates that pre-meal exercise helps regulate energy balance, but also identifies key differences in response compared with adults. Overall, current findings support the benefits of timing, but research is required to establish guidelines that are specific to the pediatric population and their health-related goals, while incorporating other FITT components.

A Systematic Review of Physical Activity Interventions in Individuals with Binge Eating Disorders

PURPOSE OF REVIEW

Our systematic review aims to assess the overall evidence available in the literature regarding the role of physical activity (PA) in individuals with binge eating disorder (BED) and better understand the potential underlying mechanisms of action.

RECENT FINDINGS

Currently, the most effective and well-established psychological treatment for BED is cognitive behavioral therapy (CBT) with a remission rate around 80%. CBT is sometimes combined with pharmacotherapy targeting comorbidities associated with BED, such as obesity and depression. Another avenue of treatment that has been less studied is PA. It has been suggested that PA addresses the underlying mechanisms of BED and, thus, increases treatment efficiency. This systematic review provides additional knowledge concerning the benefits of PA in the treatment of individuals with BED including reduction of binge eating (BE) episodes and improvement in other associated comorbidities. Potential mechanisms of action of PA include neurochemical alterations affecting the reward system, reduction of negative affect, and its anorexigenic effects.