Mealtime Physiological Responses in Individuals With Eating Disorders and Healthy Controls.

Objective: Mealtimes are highly distressing for individuals with eating disorders (ED), potentially reinforcing disordered eating and complicating recovery. Yet, physiological responses during meals remain understudied. This study explores autonomic nervous system responses during meals in individuals with ED and healthy controls (HC).

Methods: Three studies assessed heart rate (HR), heart rate variability (HRV), skin conductance response (SCR), and skin temperature (ST) around lunchtime. Study 1 included 47 hospitalized adult women with ED (26 anorexia nervosa (AN), 8 atypical AN, 13 bulimia nervosa (BN)). Studies 2 and 3 involved 47 and 58 HC in daily life.

Results: Patients reported elevated subjective stress but showed no expected physiological responses in HR. Instead, HR decreased during meals for all patients and increased after in those with BN. No significant changes were observed in HRV or SCR. No ST changes were observed in AN, while BN showed the expected pre-lunch decrease and post-lunch increase. In HC, HR and SCR rose pre-meal, HRV decreased, and ST increased during meals.

Discussion: These findings suggest a mismatch between subjective and physiological stress in ED. Chronic stress or undernutrition may alter autonomic reactivity, although not directly assessed. Future research should investigate how these factors shape physiological stress responses.