Validation of a questionnaire measure of the relative reinforcing value of food.

The traditional method of measuring the relative reinforcing value of food provides subjects a choice of food and non-food alternatives, and defines the relative reinforcing value of food based on the allocation of responses for the two alternatives as the schedules of reinforcement for the alternatives change. Greater allocation of responses for one alternative versus another reflects the relative reinforcing value of the alternatives. This method was designed for laboratory use, but methods are needed to extend measurement of reinforcing value to applied research environments. Two experiments were conducted to assess the validity of a questionnaire measure of the relative reinforcing value of food in normal weight university samples. Study 1 (n=39) assessed the relationship between the relative reinforcing value of snack food versus fruits and vegetables (condition 1) or enjoyable sedentary behaviors (condition 2) as measured by the questionnaire and standardized computerized concurrent schedules criterion. A significant relationship (Pearson r=0.49, p<0.01; Guttman's MU2=0.69) across the two conditions between the two methods of measuring food reinforcement was observed. Experiment 2 (n=10) utilized a within-subject counterbalanced design to manipulate food deprivation and hunger levels to determine if food deprivation increased the reinforcing value of snack food as measured by the questionnaire to provide an index of validity of the questionnaire. Results showed that food deprivation increased the relative reinforcing value of snack food. Results from both studies suggest that the questionnaire has good validity, and may represent an efficient and reliable method of assessing the relative reinforcing value of food.