Immediate post-exercise energy intake and macronutrient preferences in normal weight and overweight pre-pubertal children.

OBJECTIVE: To examine the immediate effect of three different types of popular exercise activities on food intake and preferences in normal weight and overweight children. SUBJECTS AND METHODS: Forty-four (22 overweight) age and gender matched, pre-pubertal children participated in four separate visits. All performed three typical, 45 min, aerobic, indoor resistance and swimming exercise sessions and a control visit (no exercise). A similar buffet lunch was served immediately after each visit to both groups. The total energy intake and relative consumption of carbohydrates, fat and protein were recorded.
RESULTS: In the normal weight children, total energy intake was reduced following exercise. This difference reached statistical significance only following the resistance-type exercise (14.0 + or - 1.4 [58.6 + or - 5.9] versus 19.4 + or - 1.7 [81.2 + or - 7.1] kcal/kg [kJ/ kg], in resistance exercise and control, respectively; p<0.008). The different types of exercise were associated with increased relative consumption of carbohydrate and decreased consumption of fat. In contrast, in the overweight children, total energy intake was increased following exercise. This increase reached statistical significance following the swimming exercise session (23.0 + or - 2.4 [96.3 + or - 10.0] versus 18.5 + or - 1.5 [77.4 + or - 6.3] kcal/kg [kJ/kg] in swimming and control, respectively; p<0.02). All types of exercise lead to a significant increase in the relative consumption of proteins in the overweight children. Finally, the total energy intake was significantly greater in the overweight children following the control (i.e., no exercise), and all types of exercise sessions. After normalization of the total energy intake to body mass, this difference remained significant only following the swimming practice (23.0 + or - 2.4 [96.3 + or - 10.0] versus 15.9 + or - 1.6 [66.6 + or - 6.7] kcal/kg [kJ/kg] in overweight and normal weight, respectively; p<0.04).
CONCLUSIONS: Understanding the complicated relationship between exercise, appetite, and food choices may help us to optimize exercise interventions for this unique population, and to select the best exercise protocols to achieve a desired energy balance. Food intake and preferences in response to acute exercise are different in normal weight and obese children.