Food-specific response inhibition, dietary restraint and snack intake in lean and overweight/obese adults: a moderated-mediation model

BACKGROUND/OBJECTIVES: The relationship between response inhibition and obesity is currently unclear. This may be because of inconsistencies in methodology, design limitations and the use of narrow samples. In addition, dietary restraint has not been considered, yet restraint has been reported to moderate performance on behavioural tasks of response inhibition. The aim of this study was to investigate performance on both a food-based and a neutral stimuli go/no-go task, which addresses current design limitations, in lean and overweight/obese adults. The moderating role of dietary restraint in the relationship between body composition, response inhibition and snack intake was also measured. SUBJECTS/METHODS: Lean and overweight/obese, males and females (N=116) completed both a food-based and neutral category control go/no-go task, in a fully counterbalanced repeated-measures design. A bogus taste-test was then completed, followed by a self-report measure of dietary restraint. RESULTS: PROCESS moderated-mediation analysis showed that overweight/obese, compared with lean, participants made more errors on the food-based (but not the neutral) go/no-go task, but only when they were low in dietary restraint. Performance on the food-based go/no-go task predicted snack intake across the sample. Increased intake in the overweight, low restrainers was fully mediated by increased errors on the food-based (but not the neutral) go/no-go task. CONCLUSIONS: Distinguishing between high and low restrained eaters in the overweight/obese population is crucial in future obesity research incorporating food-based go/no-go tasks. Poor response inhibition to food cues predicts overeating across weight groups, suggesting weight loss interventions and obesity prevention programmes should target behavioural inhibition training in such individuals.