EXERCISE-INDUCED CHANGES IN BODY FAT, BODY MASS, AND FAT-FREE MASS IN PEDIATRIC OBESITY

Purpose: The purpose of this study was to quantify the effects of exercise treatment programs on changes in body mass, fat-free mass, and body fat in obese children adolescents. Methods: Using the meta-analytic approach, studies which met the following criteria were included in our analyses: 1) at least six subjects per group; 2) subject groups consisting of children in the 5–17 year age range; 3) pre-test and post-test values for either body mass, percent body fat, or FFM; 4) used exercise as a mode of treatment (e.g. walking, jogging, cycle ergometry, high-repetition, resistance exercise, and combinations); 6) training programs ≥ 3 weeks; 7) full-length publications (not conference proceedings); 8) apparently “healthy” children (i.e.) free from endocrine diseases and disorders, and 9) published studies in English language journals, only. Results: Across all designs and categories, fixed-effects modeling yielded significant decrease in the following dependent variables: percent body fat (X = .70 ± .35; 95% CI = .21 to 1.1); FFM (X = .50 ± .38; 95% CI = .03 to .57); body mass (X = .34 ± .18; 95% CI = .01 to .46); BMI (X = .76 ± .55; 95% CI = 4.24 to 1.7, and VO2 max (X. = .52 ± .16; 95% CI = .18 to .89), respectively. Significant differences were found as a function of the type intervention groups (exercise vs. exercise + behavior modification; P < 0.04, body composition assessment methods (skinfold vs. hydrostatic weighing, DEXA, and total body water; P < 0.006), exercise intensity (60–65% vs. ≥ 71% VO2 max; P < 0.01), duration (≤ 30 min vs. > 30 min; P < 0.03) and mode (aerobic vs. aerobic + resistance training, P < 0.02). Stepwise linear regression suggested that initial body fat levels (or body mass), type of treatment intervention, exercise intensity, and exercise mode accounted for most of the variance associated with changes in body composition following training. Conclusions: Exercise is efficacious for reducing selected body composition variables in children and adolescents.