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

Objective: Identifying factors that control food intake is crucial to the understanding
and treatment of eating disorders characterized by binge eating. In healthy individuals, stomach
distension plays an important role in the development of satiation, but gastric sensations might
be overridden in binge eating. The present study investigated the perception of gastric signals
(i.e., gastric interoception) and gastric motility in patients experiencing binge eating episodes,
i.e. bulimia nervosa (BN) and binge-eating disorder (BED). Method: Twenty-nine patients with
BN or BED (ED group) and 32 age-, sex-, and BMI-matched healthy controls (HC group)
participated in the study. The onset of satiation and stomach fullness were assessed using a
novel 2-step water load test (WLT-II). Gastric myoelectrical activity (GMA) was measured by
electrogastrography (EGG) before and after ingestion of non-caloric water. Results: Individuals
in the ED group drank significantly more water until reporting satiation during the WLT-II. The
percentage of normal gastric myoelectrical power was significantly smaller in the ED group
compared to HC, and negatively related to the number of objective binge-eating episodes per
week in bulimic patients. Power in the bradygastria range was greater in ED than in HC
subjects. Discussion: Patients with EDs have a delayed response to satiation compared to HC
participants, together with abnormal GMA. Repeated binge eating episodes may induce
disturbances to gastric motor function.