REINFORCING VALUE OF FOOD IN OBESE AND NONOBESE WOMEN

Food is a powerful reinforcer, and individual differences in the reinf orcing efficacy of food may provide a mechanism to explain the excess intake and positive energy balance responsible for obesity. The presen t study tested the hypothesis that eating palatable food would be more reinforcing than engaging in sedentary activities (e.g. playing compu ter games) for obese in comparison to non-obese non-dietary restrained female college students. Subjects could choose to eat food or engage in sedentary activities based on their responding in a computer-genera ted concurrent schedules task. The reinforcement schedule associated w ith earning access to sedentary activities was held at variable ratio 2 (VR2) while the food reinforcement schedule was set at VR2 in the fi rst trial of the choice task and doubled across the four subsequent tr ials from VR4 to VR32. Choice and consumption results indicated that e ating was significantly more reinforcing than engaging in sedentary ac tivities for obese subjects than non-obese subjects. Hedonics for the activities and foods were not correlated with total food reinforcers e arned and did not differ between the groups. These results confirm the hypothesis that eating food is more reinforcing than selected alterna tive activities to a greater extent for obese than for non-obese young women. (C) 1996 Academic Press Limited