'Food addiction' and its association with a dopaminergic multilocus genetic profile

•Food addiction (FA) is associate with enhanced dopamine signaling.•Overeating facilitates relationship between FA and dopamine genetic markers.•FA appears to be a reward-responsive phenotype of obesity.

BackgroundOur objective was to employ a novel genetic methodology - whereby functional variants of the dopamine pathway were aggregated to reflect a polygenic liability - in the study of food addiction. We anticipated that the composite index of elevated dopamine signaling (a multilocus genetic profile score [MLGP]) would distinguish those with a designation of food addiction (according to the Yale Food Addiction Scale [YFAS] criteria), and age and weight equivalent controls. Our second aim was to assess whether this index was positively associated with eating-related sub-phenotypes of food addiction (e.g. binge eating and food cravings).MethodsAdults (n = 120) recruited from the community were solicited for an overeating/overweight study. Eating-behavior questionnaires were completed and a blood sample was taken for genotyping.Results and conclusionsThe YFAS identified 21 participants with food addiction. As predicted, the MLGP score was higher in those with YFAS-diagnosed food addiction, and it correlated positively with binge eating, food cravings, and emotional overeating. We then tested a multiple-mediation model proposing that reward-driven overeating facilitates the relationship between the MLGP score and food addiction. The model was statistically significant, supporting the view that the relationship between a composite genetic index of dopamine signaling and food addiction is mediated by certain aspects of reward-responsive overeating.