Smoking, dietary restraint, gender, and the relative reinforcing value of snack food in a large university sample

The present study examined the independent and interactive association between smoking, gender, dietary restraint and the relative reinforcing value of snack food in a university sample. Four hundred and three introductory psychology students completed questionnaires assessing age, gender, BMI, hunger, smoking status, nicotine dependence, dietary restraint, hedonic ratings and the relative reinforcing value of snack food and fruits and vegetables. The relative reinforcing value of snack food was determined by the number of button presses subjects would be willing to do to obtain (100 g) of snack food versus 100 g of fruits and vegetables. Multiple regression analyses yielded a significant three-way interaction of gender, restraint, and smoking in predicting the relative reinforcing value of snack food indicating that in female smokers, dietary restraint was inversely associated with the relative reinforcing value of snack food, whereas in male smokers, restraint was not significantly related with the reinforcing value of snacks. These findings remained significant after controlling for BMI, hunger, and hedonics, suggesting that there are gender differences in relationship between smoking, dietary restraint, and snack food reinforcement. Among female university students, smoking moderates the relationship between dietary restraint and food reinforcement whereby high-restraint female smokers appear to be at lower risk of over-consuming energy dense snack food compared to low-restraint female smokers, while high-restraint male smokers may not be at higher risk than low-restraint male smokers.