Objective: This study examined the 24-month outcomes of a randomized controlled trial of a group-based behavioral weight control (BWC) program combined with either activity-based peer intervention or aerobic exercise.
Methods: At baseline, 118 obese adolescents (68% female; BMI = 31.41 ± 3.33) ages 13 to 16 years (mean = 14.33; SD = 1.02) were randomized to receive 1 of 2 weight loss interventions. Both interventions received the same 16-week group-based cognitive-behavioral treatment, combined with either aerobic exercise or peer-based adventure therapy. Eighty-nine adolescents (75% of original sample) completed the 24-month follow-up. Anthropometric and psychosocial measures were obtained at baseline, at the end of the 16-week intervention, and at 12 and 24 months following randomization.
Results: An intent-to-treat mixed factor analysis of variance indicated a significant effect for time on both percent over 50th percentile BMI for age and gender and standardized BMI score, with no differences by intervention group. Post hoc comparisons showed a significant decrease in percent overweight at 4 months (end of treatment), which was maintained at both 12- and 24-month follow-up visits. Significant improvements on several dimensions of self-concept were noted, with significant effects on physical appearance self-concept that were maintained through 24 months.
Conclusions: Both BWC conditions were effective at maintaining reductions in adolescent obesity and improvements in physical appearance self-concept through 24-month follow-up. This study is one of the first to document long-term outcomes of BWC intervention among adolescents.