Previous research showed a strong relation between response inhibition, overeating and overweight. It was shown that people with ineffective response inhibition are more susceptible to the temptations of palatable food, eat more and are more often overweight or obese. In addition the results of several studies suggest that what needs to be inhibited may be an affect-driven motivation for food. In the present longitudinal study, we therefore investigated the interplay of response inhibition and implicit preferences for snack foods in predicting weight gain. In a sample of predominantly normal weight undergraduate female students, implicit preference for food, response inhibition, and body mass index (BMI) were measured. After 1 year, BMI was measured again. Weight gain of the participants over a 1-year period. The results strongly confirmed our expectations: participants with strong implicit preferences for snack foods and low inhibitory capacity gained the most weight. These findings imply that ineffective response inhibition may render people vulnerable to excessive or impulsive behavior in general, but that the manifestation thereof is determined by domain-specific preferences or needs.