Mealtime Physiological Responses in Individuals With Eating Disorders and Healthy Controls

Abstract

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.

Highlights

Mealtimes are associated with higher levels of psychological stress in individuals with anorexia nervosa and bulimia nervosa and can be considered as an eating disorder-specific stressor.

Despite reporting high stress, physiological stress markers (heart rate variability, skin conductance, and skin temperature) do not clearly indicate a stress response in these individuals.

Autonomic nervous system changes observed during lunch in healthy controls are not related to subjective stress.