Discontinuing nicotine intake usually results in weight gain partially due to heightened energy intake from between-meal snacks. This experiment tested the hypothesis that the reinforcing value of palatable carbohydrate-rich snacks increases for female smokers during nicotine deprivation. Eighteen smokers and 18 nonsmokers completed a concurrent-schedules operant computer task on two separate days. Smokers were bio-verified abstinent at the second testing. The operant task allowed participants to earn points redeemable for either carbohydrate snacks or money on concurrent variable-ratio schedules of reinforcement. There were five different probabilities of earning points redeemable for snacks (8%, 16%, 25%, 50%, 75%), while the probability of earning points redeemable for money remained fixed at 25%. Reward value of snacks was measured by switch point: the reinforcement ratio at which the effort required to earn snacks exceeded their value to the respondent, as signified by a shift to working for money. Results showed that smokers undergoing nicotine deprivation persisted in working for snacks into leaner reinforcement schedules than nonsmokers (P=.026). Furthermore, nicotine deprivation increased smokers' allocation of effort to earn snack foods relative to their own behavior when smoking (P=.006). Variation in palatability or hunger did not explain these differences in snack reward value. Findings indicate that nicotine deprivation is associated with a heightened reward value of appealing snack foods for female smokers.
Available at: http://works.bepress.com/sherry_pagoto/6/