Gastric interoception and gastric myoelectrical activity in bulimia nervosa and binge eating disorder

Abstract

A better understanding of the factors that control food intake and meal termination is crucial for models and treatment of eating disorders in which binge eating is a core feature. As a digestive organ and periodic reservoir for ingested food, the stomach plays an important role for satiation. Nevertheless, little is known about gastric interoception or gastric motility in patients experiencing binge eating, i.e. bulimia nervosa (BN) and binge-eating disorder (BED). The present study investigated individual sensitivity for the onset of satiation and maximum stomach fullness in patients with BN or BED (ED group; n = 29) and in healthy controls (HC group; n = 32). In addition, gastric myoelectrical activity was measured before and after ingestion of non-caloric water. The onset of satiation and stomach fullness were assessed using a novel 2-step water load test (WLT-II). Gastric myoelectrical activity was measured by electrogastrography (EGG) during 15 minutes before and after water ingestion. ED participants drank significantly more water until feeling satiated during the WLT-II. After water ingestion, the percentage of gastric activity in the 3 cpm normogastria range was significantly lower in ED compared to HC participants. Power in the 1-2.5 cpm bradygastria range was higher in ED than in HC subjects. Percentage of normogastria was strongly negatively related to the number of objective binge-eating episodes per week in bulimic patients. ED patients have a delayed response to satiation compared to HC participants, together with abnormal gastric myoelectrical activity. Frequent binge eating may induce disturbances to gastric motor function.