Does inhibitory control capacity in overweight and obese children and adolescents predict success in a weight-reduction program?

It has been assumed that inhibitory control capacity might influence the success of overweight or obese subjects in reducing weight. However, empirical research on this association is scarce. The present study, therefore, examines whether success in an outpatient weight-reduction program for children and adolescents can be predicted by pre-intervention inhibitory control capacity. The study sample consisted of 111 overweight and obese children and adolescents (7.5-15 years) who attended an outpatient weight-reduction program of 1 year's duration. Inhibitory control was assessed by two computerized neuropsychological procedures, a Go-NoGo and an interference task. Principal component analysis revealed "impulsivity" (fast but less valid reactions) and "inattention" (slow and highly variable reaction times) component. Those who succeeded in the intervention (losing more than 5% of BMI-SDS; n = 63) scored significantly higher in the first component than those who failed, while controlling for pre-intervention BMI-SDS, age, gender, and maternal education level. The association was moderated by age. Although in younger children no effect was found, in adolescents high "impulsivity" predicted success. Our result supports the scant evidence for a role of inhibitory control. However, further studies are required to substantiate that weak inhibitory control, and thus high reactivity to external cues, entails a better outcome in behavior modification interventions.