AbstractThe present study evaluated the association of food addiction (FA), the change of the BMI/age z-score and the consumption of ultra-processed foods in overweight students undergoing a 16-month, multicomponent intervention in the school environment. FA was investigated using the Yale Food Addiction Scale for Children, and the dietary assessment was estimated using the semi-quantitative FFQ in overweight 9–11-year-old students (BMI/age z-score ≥ 1) of both sexes at their baseline and after the intervention (n 120). Among the schoolchildren, 33·4 % had FA in at least one of the two assessments. The analysis of mixed-effects models to assess the effect of the intervention and the change of the BMI/age z-score between evaluations showed that the occurrence of FA influenced the maintenance of weight (time#FA, β = 0·30, 95 % CI 0·05, 0·54, P = 0·016). Weight loss was observed only in individuals who did not present FA (BMI/age z-score = −0·3). When evaluating the effect of the intervention and the dietary variables, we verified a reduction in the consumption of sugary milk-based drinks −71·13 kJ (–17 kcal), P = 0·04 only in non-FA students at the end of the study. FA has been identified as an underlying factor with therapeutic relevance, and an enhanced understanding of FA can open new paths for the prevention and management of obesity.