Food reinforcement, dietary disinhibition and weight gain in nonobese adults

OBJECTIVE: Food reinforcement is cross-sectionally related to BMI and energy intake in adults, and prospectively predicts weight gain in children, but there has not been any research studying food reinforcement as a predictor of adult weight gain. DESIGN AND METHODS: This study examined whether the relative reinforcing value of food versus sedentary activities, as measured on a progressive ratio schedule, predicts 12-month weight gain in a sample of 115 nonobese (BMI < 30) adults. Dietary disinhibition and dietary restraint were also examined as potential moderators of this relationship. RESULTS: In a hierarchical regression controlling for baseline age and weight, dietary hunger, income, sex, and minority status, food reinforcement and predicted weight gain (P = 0.01) significantly increased the variance from 6.3% to 11.7% (P = 0.01). Dietary disinhibition moderated this relationship (P = 0.02) and increased the variance an additional 4.7% (P = 0.02), such that individuals with high food reinforcement had greater weight gain if they were also high in disinhibition. CONCLUSIONS: These results suggest that food reinforcement is a significant contributor to weight change over time, and food reinforcement may have the biggest effect on those who are most responsive to food cues.