Alcohol's acute effect on food intake is mediated by inhibitory control impairments

There is a strong association between alcohol misuse and excess weight. Although alcohol is highly calorific and may directly contribute to weight gain, it is also likely to have indirect effects on weight. Indeed, alcohol primes have been found to stimulate appetite and increase energy intake in experimental taste tests. The current study investigated whether the effects of alcohol on energy intake are the result of inhibitory control impairments and whether this effect is moderated by individual differences in dietary restraint.

Sixty undergraduate females completed measures of dietary restraint and the Food Craving Questionnaire-State (FCQS). Following this, they were given an alcohol prime (0.6 g of alcohol per kg of body weight) or a placebo drink manipulated to smell and taste alcoholic. Participants then completed another FCQS and a color conflict Stroop to measure inhibitory control. Finally, participants were asked to taste cookies for 15 minutes.

Participants in the alcohol condition performed worse on the Stroop (d = .61) and consumed more cookie calories (d = .61) than participants in the placebo condition. Notably, the effect of the experimental condition on the amount of cookies consumed was mediated by Stroop performance (Κ2 = .08), although this effect was not evident under high levels of restraint. There was no effect of experimental condition on any subscale of craving.

The current study suggests that increased energy intake after alcohol administration may be the product of inhibitory control impairments. However, the most restrained eaters are able to maintain control over their eating behavior.