The Role of Meal Timing in Appetitive Responses to Acute Exercise in Adolescents with and without Obesity: A...

Physical activity has been shown to improve various aspects of metabolic health and is frequently applied as an intervention in the management and prevention of overweight/obesity. Chrono-exercise can be studied in relation to time of day and timing in relation to a meal, which encompasses chronology and duration of the temporal interval, but the latter has received limited attention to date. This brief review and meta-analysis investigates whether the timing of a meal subsequent to acute exercise in children and adolescents with and without overweight/obesity moderates eating behavior and appetite. A quantitative synthesis of 28 controlled trials with 51 distinct conditions (N = 575; median sample size = 15, median age = 13 y, n = 297 overweight/obesity) was performed using multilevel random-effects meta-regressions and restricted splines to test the linear and nonlinear relationships between mean differences in energy intake between exercise and control conditions and the duration of the exercise-test meal interval, and if this moderated by participant weight status or exercise characteristics (i.e., intensity, duration, and method). Commencement of meals occurred from immediately to 3 h after cessation of exercise (median = 30 min, interquartile range = 8 min). The meal interval was not associated with effect sizes overall in the linear and spline analysis (ps = 0.576 and 0.971, respectively). Although there was only an interaction with weight status present in the linear analysis (P < 0.001), the meal interval significantly moderated effect sizes within-study arms with lean participants (ps = 0.006 and 0.019, respectively), but not in those with overweight/obesity (ps = 0.070 and 0.620, respectively) in both analyses. Exercise characteristics did not have an impact on this relationship. Taken together, prescriptions for meal timing may depend on the individual phenotype when seeking to optimize potential anorexigenic effects of acute exercise. This trial was registered at PROSPERO as CRD42021287838. (https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=287838).