Childhood Obesity Intervention Trial: Participant Criteria

Inclusion criteria for participation in CHILT III were, in addition to age and the BMI percentiles mentioned above, e.g., sufficient motivation of children and guardians and active, regular participation, whereas mental or eating disorders or insufficient group ability were considered exclusion criteria for the program. The minimum requirement for each participant to be included in this analysis was participation in the 11-month intervention from beginning to end and complete data on parental education and BMI-SDS at baseline and program end. Further exclusion criteria for this study were missing data at follow-up on BMI-SDS, cardiovascular endurance, physical self-concept, self-worth, or media use (Fig. 1). A final data set of 237 children and adolescents (54% girls) and their parents (n = 449: 235 mothers; 214 fathers) remained. An a priori power analysis performed with G*Power 3.1 indicated that at least 83 participants were required for this study in order to perform a multiple linear regression analysis with 15 predictors, a desired large effect size (f² = 0.4), and a power of 0.95 at an alpha level of 0.05 [30 (link)].Fig. 1

Flowchart of number of participants of this study. CHILT, Children’s Health Interventional Trial; BMI-SDS, body mass index standard deviation scores