Longitudinal changes in activity patterns, physical capacities, energy expenditure, and body composition in severely obese adolescents during a multidisciplinary weight-reduction program

OBJECTIVE: To determine the longitudinal changes in body composition, physical capacities, and time and energy expenditure (EE) devoted to various activities in the course of a 9-month weight-reduction period. DESIGN: Longitudinal, clinical intervention including lifestyle education, moderate energy restriction, progressive training, and psychological follow-up. SUBJECTS: A total of 27 (13 boys and 14 girls) severely obese adolescents (mean BMI: 33.9 kg/m 2 ; 41.5% fat mass (FM)), aged 12–16 y. MEASUREMENTS: Before the beginning and after the weight-reduction program, body composition was assessed by dual-energy X-ray absorptiometry (DXA), physical capacities by multistage treadmill test, and EE both by whole-body calorimetry and in free-living conditions using the heart rate-recording method. During 8 months of the weight-reduction period, type and duration of each activity were recorded using a daily controlled activity diary. RESULTS: One boy resigned after 5 months. Body weight (BW) and FM decreased (−19 and −42%, respectively, P