Impact of imposed exercise on energy intake in children at risk for overweight

Abstract

BackgroundExercise not only has a direct effect on energy balance through energy expenditure (EE), but also has an indirect effect through its impact on energy intake (EI). This study examined the effects of acute exercise on daily ad libitum EI in children at risk for becoming overweight due to family history.MethodsTwenty healthy-weight children (ages 9–12 years, 12 male/8 female) with at least one overweight biological parent (body mass index ≥ 25 kg/m2) participated. Children reported to the laboratory for one baseline and two experimental visits (EX = exercise, SED = sedentary) each separated by 1 week in a randomized crossover design. Two hours into the EX day session, children exercised at 70 % estimated VO2max for 30 min on a cycle ergometer. Objective EI (kcal) was measured at a standard breakfast (~285 kcal) and ad libitum lunch, snack and dinner. Meals were identical on the EX and SED days. Activity-related EE (kcal) was estimated with accelerometers worn on the non-dominant wrist and ankle. Relative EI (kcal) was computed as the difference between Total EI and Activity-related EE for each testing day. Paired t-tests were performed to test differences in Total EI, Activity-related EE and Relative EI between the EX and SED days.ResultsAcross all meals, Total EI was not statistically different between the EX and SED days (t = 1.8, p = 0.09). Activity-related EE was greater on the EX day compared to the SED day (t = 10.1, p < 0.001). By design, this difference was predominantly driven by activity during the morning (t = 20.4, p < 0.001). Because children consumed a similar number of kcal on each day, but had greater Activity-related EE on the EX day, Relative EI was lower (t = −5.15, p < 0.001) for the EX day (1636 ± 456 kcal) relative to the SED day (1862 ± 426 kcal).ConclusionsImposed exercise was effective in reducing Relative EI compared to being sedentary. Morning exercise may help children at risk for becoming overweight to better regulate their energy balance within the course of a day.

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

“…Although in their study questioning the impact of an acute intensive cycling bout (70% V̇O 2max ) among pre‐pubertal children at risk for overweight/obesity (defined as having at least one parent with obesity), Fearnbach and collaborators did not find any subsequent differences in EI compared with a non‐exercise control day. In this study, FFM index (FFM (kg) /height (m 2 )) was positively associated with EI on the exercise but not the control day, suggesting a better homeostatic EI regulation with imposed exercise in this sample . This is particularly interesting since the homeostatic regulation of energy balance is not limited to the metabolic changes associated with EE fluctuations and that body composition has been shown to be involved in the regulation of EI, FFM being a good predictor of EI (better than FM) in both adolescents and adults .…”

Brain reactivity to visual food stimuli after moderate-intensity exercise in children

“…The relationship between exercise and neural response to food pictures has also recently been investigated in adolescents using event-related potentials (ERPs) to demonstrate that food stimuli resulted in lower neural activation (i.e., decreased amplitude of the P3b ERP component) following exercise compared to non-food stimuli (Fearnbach et al 2016). The difference in neural activity between food and non-food stimuli was not present following sedentary activity (Fearnbach et al 2016). However, the extent to which the relationship between the brain response to food-related stimuli and exercise exists in children is not yet known.…”

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

“…While not specially designed and focused on the effect of the exercise-timing, results from studies using similar exercises and conducted among similar populations tend to suggest potentially different energy intake responses depending on the delay between exercise and the subsequent meal. In their work, Fearnbach et al for instance showed reduced ad libitum energy intake in 12-15 years old adolescents with obesity 30 minutes after an acute bout of moderate intensity cycling exercise [34,35] while others failed to observe any food consumption modification in a similar population when the same exercise is performed 60 minutes before lunch [36].…”