Relative Reinforcing Value of Energy-dense Snack Foods: In Overweight and Obese Adults

Abstract

Purpose: Obese people find energy-dense food more reinforcing than do their non-obese peers, and reinforcement influences food intake. We examined how the degree of adiposity, measured by body mass index (BMI), is associated with the relative reinforcing value of energy-dense snack foods versus fruits and vegetables in overweight and obese people. Methods: Ninety-two overweight or obese students in introductory psychology courses completed questionnaires on age, sex, BMI, hunger, smoking status, dietary restraint, and hedonic (liking) ratings for energy-dense snack foods and fruits and vegetables. The questionnaire also was used to evaluate the relative reinforcing value of these snack foods in comparison with fruits and vegetables. Results: The BMI predicted the relative reinforcing value of energy-dense snack food. This positive relationship remained significant after we controlled for age, sex, dietary restraint, hunger, smoking status, and snack food hedonics. Conclusions: The greater the degree of overweight and obesity, the greater the motivation to obtain energy-dense snack foods. Because the rewarding value of food is a strong determinant of energy intake, a useful approach to preventing and treating obesity may be introducing pharmacological or behavioural nutrition intervention to reduce the rewarding value of energydense snack foods, or increasing the rewarding value of fruits and vegetables.