Oxytocin increases food intake and modulates food stimulus processing in females with or without binge eating disorder

Binge eating disorder (BED) is maintained by increased food-related incentive salience, which is reflected by an attentional bias for food. Oxytocin attenuates this attentional bias in patients with anorexia nervosa and reduces hedonic (i.e., mainly reward-driven) food intake in males with normal or increased body weight, but results in individuals with BED are inconclusive. We assessed the acute effect of oxytocin on the processing of food stimuli and on eating behavior in BED in a double-blind, placebo-controlled cross-over study. Females with BED (n = 48) and female control participants with overweight (OWC; n = 46) or normal weight (NWC; n = 40) received intranasal oxytocin after a standardized breakfast following an overnight fast; in participants with natural menstrual cycle, sessions were scheduled during consecutive luteal phases. Participants completed a food-related dot-probe task with concurrent eye tracking and a bogus taste test measuring snack intake. Dwell time bias on food stimuli as well as calorie intake were the main dependent variables. We found an increase in dwell time bias due to oxytocin compared to placebo in the BED relative to the OWC group, in which this relationship was reversed. Contrary to our hypothesis, oxytocin significantly increased hedonic food intake across groups. The latter effect was restricted to females taking hormonal contraception. These results provide support for the assumption of disorder- and, respectively, sex-specific effects of oxytocin on food-related incentive salience and hedonic food intake. They moreover suggest that sex hormones determine the acute effect of oxytocin on eating behavior in females.