Will work for snack food: the association of BMI and snack reinforcement.

It has been suggested that for overweight and obese individuals high-calorie foods are more reinforcing than for normal-weight individuals. It has already been shown that in contrast to sedentary activities, snack food is more reinforcing for obese women, relative to normal-weight women. However, it is unclear whether overweight/obese individuals are more sensitive to the reinforcing value of food in general or more specifically to the reinforcing value of high-calorie foods. This was tested in the present study, with overweight/obese and normal-weight individuals performing a concurrent schedules task, which measures how hard someone is prepared to work for high-calorie snacks compared to low-calorie foods (e.g., fruits, vegetables), when both foods are equally liked. By gradually increasing the amount of work required to earn snacks, the relative-reinforcing value of snacks was determined. As hypothesized, overweight/obese individuals work harder for high-calorie snacks compared to normal-weight individuals.