Effects of stress on chewing and food intake in patients with anorexia nervosa.

Objective: The present study investigates the impact of psychosocial stress on chewing and eating behavior in patients with anorexia nervosa (P ).

Method: The eating and chewing behavior of P were examined in a standardized setting by means of a chewing sensor. These procedures encompassed n = 19 P , age, and gender matched to n = 19 healthy controls (HC). Food intake and chewing frequency were assessed in two experimental conditions: rest versus stress (via Trier Social Stress Test). To verify stress induction, two appraisal scales were employed. In addition, chronic stress, psychological distress and eating disorder symptoms were assessed.

Results: In terms of food intake and chewing frequency, the results of the 2x2 ANOVA demonstrated a significant effect of condition and group. During stress, all participants demonstrated a higher chewing frequency and a decreased ingestion. In general, patients ate less at a lower chewing frequency (vs. HC). However, sample specific analyses demonstrated that the eating and chewing behavior of P remained unchanged regardless of the condition, except for their drinking. Food choices were comparable between the groups, but appetite values significantly differed.

Discussion: The increase in chewing frequency in all participants during stress suggests that chewing might impact affect regulation, however, not specifically in P . Future research should clarify to what extent the normalization of chewing behavior could ameliorate ED-symptoms (incl. food intake) in P . The application of a chewing sensor could support this aim and future interventions.