Association between inhibitory control capacity and body weight in overweight and obese children and adolescents: dependence on age and inhibitory control component.

It has been assumed that overweight individuals show weak inhibitory control capacity leading to a failure to resist external cues for palatable food and that this deficit underlies the recently reported empirical association between obesity and attention deficit/hyperactivity disorder (ADHD). In childhood and adolescence, empirical research on this issue is scarce. Here, the hypothesis is tested that high body weight is associated with weak inhibitory control performance and that this association is moderated by age. The sample included 177 overweight and obese children and adolescents (BMI: M = 29.2, SD = 4.33; BMI-SDS: M = 2.45, SD = 0.43) between 8 and 15 years. Inhibitory control was assessed by a Go/No-Go task and an Interference Task. A principal component analysis yielded two components: impulsivity (fast but invalid responses) and inattention (highly variable reaction times). While controlling for age, gender, and maternal education level, we found that more obese children/adolescents showed more inattention. As indicated by a significant interaction effect, exclusively at younger ages, high impulsivity was associated with high body weight. The results thus confirm a link between low inhibitory control capacity and high body weight and might point to a developmental period with heightened significance of impulsivity for weight gain.