Transactions among thinness expectancies, depression, and binge eating in the prediction of adolescent weight control behaviors

Objective: Binge eating, the transdiagnostic risk associated with depression, and the eating disorder-specific risk associated with expectancies for reinforcement from thinness have been identified as risk factors for the development of weight control behaviors. The purpose of this study was to examine if these risk factors transact to further predict risk in youth. Method: Binge eating, depressive symptoms, thinness expectancies, and weight control behaviors were assessed in 1,758 adolescents three times during the transitional period between middle school and high school. We tested six different possible transactional processes. Results: Mediation tests demonstrated that both 8th grade binge eating and 8th grade depressive symptoms predicted 10th grade weight control behaviors through their predictive influence on thinness expectancies in 9th grade. However, our results were not consistent with a mediational process in which 8th grade thinness expectancies predicted 9th grade depression to further predict 10th grade weight control behaviors. No interactions among binge eating, depressive symptoms, or thinness expectancies predicted weight control. Results did not differ between girls and boys. Discussion: Thinness expectancies appear to mediate the predictive influence of binge eating and depressive symptoms on risk for engaging in weight control behaviors. These results add to theoretical understanding of risk and suggests potential intervention pathways for clinicians.