The Influence of Food Reinforcement and Eating Disorder Pathology on Weight Change in Adolescents (P21-057-19)

Abstract

Abstract Objectives Both the relative reinforcing value (RRV) of food, or the motivation to obtain food, and eating disorder (ED) pathology have been shown to independently predict weight gain. However, less is known about how the interaction between the RRV of food and ED pathology predicts weight gain over time. Therefore, the purpose of this study was to examine the combined effects of the RRV of food and ED pathology on weight change over 6 months in a sample of adolescents. Methods Participants included 77 12–14 year old adolescents participating in a longitudinal study examining factors that predict changes in weight status. Data presented are from baseline and 6 months. The RRV of food was assessed using a computer task. Participants earned points for energy dense food by pressing a mouse button on a computer across escalating schedules of reinforcement. Participants were classified as “low” or “high” in RRV based on a median split of their total responses. Global ED pathology was assessed at baseline using adolescent self-report on the Eating Disorder Examination Questionnaire. Participants were classified as “low” or “high” in ED pathology based on a median split of their global ED pathology. Four groups were created: low ED pathology/low RRV (n = 20), high ED pathology/low RRV (n = 23), low ED pathology/high RRV (n = 15), and high ED pathology/high RRV (n = 19). Height and weight were measured at both baseline and 6 months and used to calculate zBMI. ANOVA was used to examine differences in zBMI change over 6 months by RRV/ED pathology group. Results zBMI change from baseline to 6 months differed by RRV/ED pathology group (P < .05). Changes in zBMI over 6 months were as follows: - 0.025 ± 0.298 for low ED pathology/low RRV; 0.010 ± 0.322 for high ED pathology/low RRV; - 0.095 ± 0.181 for low ED pathology/high RRV; and 0.186 ± 0.268 for high ED pathology/high RRV. Follow-up contrasts revealed that the high ED pathology/high RRV group experienced greater zBMI changes than the other groups (ps < 0.05). Conclusions While the RRV of food and ED pathology are both independently associated with weight gain, the current study indicates that there may be something unique about the combination of high RRV of food and high ED pathology related to risk of weight gain. Future work is needed to identify strategies to limit weight gain in this vulnerable population. Funding Sources National Institutes of Health.