Physical Activity, Energy Expenditure and Intake in 11 to 12 Years Old Japanese Prepubertal Obese Boys

抄録

The purpose of this study is to find out the differences in physical activity (PA), energy expenditure (EE) and energy intake (EI) under free-living conditions between Japanese prepubertal obese and nonobese boys. The subjects were 15 prepubertal obese boys (Age: 11.7±0.4 years old, Body fat: 35.2±1.6%) who do not have obese parents and siblings and 15 prepubertal nonobese boys (Age: 11.8±0.4 years old, Body fat: 18.5±0.8%). We assessed their daily PA by heart rate (HR) monitoring, pedometer step counts (PSC) and time for sedentary activities (SA). We also examined calculated EE from HR-VO₂ regression, EI and percentage of macronutrient EI. Results are as follows: Percentage of body fat had significant correlation with weight, BMI, time for SA, percentage EI of protein (positive, p<0.001), VO_2max, VO_2max per body weight, VO_2max per LBM, PSC, TEE per body weight, TEI per body weight (negative, p<0.001), percentage of EI of carbohydrate (negative, p<0.01). The values of the obese were significantly lower in total EE per body weight and in total EI per body weight. EI from dinner was significantly higher in the obese group. The values of the obese were significantly higher in percentage EI from protein and that from carbohydrate. The results of this study showed prepubertal obese boys who do no't have obese parents and siblings have low PA and spend much time for sedentary activities. Obese boys consume higher percentage energy of protein and lower percentage of carbohydrate though differences in EE and EI were found only in total EE per body weight and total EI per body weight between obese boys and nonobese boys.