No abstract

These results are consistent with basic animal research showing that sugar is related to food reward and with the hypothesis that food reward processes are more strongly related to eating than are food hedonics. This trial was registered at clinicaltrials.gov as NCT00962117.

Obesity is, in part, a result of positive energy balance or energy intake exceeding physiological needs. Excess energy intake is determined by a series of food choices over time. These choices involve both motivational and executive function processes. Problems arise when there is excessive motivation to eat and low impulse control, a situation we have termed reinforcement pathology. Motivational and executive function processes have also been implicated in the development of drug dependence and addiction. In this review we discuss the application of reinforcement pathology to obesity, and implications of this approach for obesity treatment.

ObjectiveFood reinforcement and delay discounting (DD) predict Body Mass Index (BMI), but there is no research studying whether these variables interact to improve prediction of BMI.Design and MethodsBMI, the relative reinforcing value of high (PMAXHED) and low (PMAXLED) energy dense food, and DD for $10 and $100 future rewards (DD10, DD100) were measured in 199 adult females.ResultsPMAXHED (p = 0.017), DD10 (p = 0.003) and DD100 (p = 0.003) were independent predictors of BMI. The interaction of PMAXLED X DD10 (p = 0.033) and DD100 (p = 0.039), and PMAXHED X DD10 (p = 0.041) and DD100 (p = 0.045) increased the variance accounted for predicting BMI beyond the base model controlling for age, education, minority status, disinhibition and dietary restraint. Based on the regression model, BMI differed by about 2 BMI units for low versus high food reinforcement, by about 3 BMI units for low versus high DD, and by about 4 BMI units for those high in PMAXHED but low in DD versus high in PMAXHED and high in DD.ConclusionsReducing DD may help prevent obesity and improve treatment of obesity in those who are high in food reinforcement.

ObjectiveFood reinforcement is cross-sectionally related to body mass index 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 MethodsThis study examined whether the relative reinforcing value of food versus sedentary activities, as measured on a progressive ratio schedule, predicts 12 month weight gain. Dietary disinhibition and dietary restraint were also examined as potential moderators of this relationship, in a sample of 115 non-obese (Body Mass Index< 30) adults.ResultsIn a hierarchical regression controlling for baseline age and weight, dietary hunger, income, sex and minority status, food reinforcement significantly increased the variance from 6.3% to 11.7% (p = 0.01) and predicted weight gain (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.ConclusionsThese 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.