Long-term effects of the RealFit intervention on body composition, aerobic fitness, and behavior

RealFit is a 13-week weight reduction program for youth that focuses on nutrition, physical activity (PA), psychology, and parental participation. The short-term effectiveness of the RealFit intervention, in terms of body composition, aerobic fitness, and dietary and PA behavior, having been proven, the present study evaluated the long-term effects of the intervention. The study had a quasi-experimental design. Height, weight, waist circumference, aerobic fitness, and self-reported dietary and PA behavior were assessed at baseline (T(0)), immediately after the 13-week RealFit intervention (T(1)), after 5 months (T(2)), and 1 year (T(3)) of follow-up. A total of 86 adolescents participated in the intervention group. The control group (n=32) comprised overweight adolescents who did not receive any treatment. One year after the RealFit intervention, significant decreases in BMI z-score (mean difference [MD]: -0.39) and waist circumference (MD, -3.24) were found. The comparison between the intervention and control groups, controlling for confounders, resulted in a significant difference (BMI z-score: -0.41; 95% confidence interval [CI]: -0.67 to -0.15; waist circumference: -8.07; 95% CI: -11.58 to -4.56). The results for dietary and PA behavior consistently showed favorable changes in the intervention group. The RealFit intervention appears to have significant favorable long-term effects on BMI z-score and waist circumference. These changes in body composition obviously represent changes in adolescents' energy balance-related behavior. Taking all results and limitations into account, it may cautiously be concluded that RealFit is an effective weight loss intervention.