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

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

The eating and chewing behavior of P_AN were examined in a standardized setting by means of a chewing sensor. These procedures encompassed n = 19 P_AN , 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.

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_AN remained unchanged regardless of the condition, except for their drinking. Food choices were comparable between the groups, but appetite values significantly differed.

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