Oxytocin Response to Food Intake in Avoidant/Restrictive Food Intake Disorder.

Abstract

To investigate the response of anorexigenic oxytocin to food intake among adolescents and young adults with avoidant/restrictive food intake disorder (ARFID), a restrictive eating disorder characterized by lack of interest in food or eating, sensory sensitivity to food, and/or fear of aversive consequences of eating, compared to healthy controls (HC). Cross-sectional. 109 participants (54 with ARFID spectrum and 55 HC) were instructed to eat a ∼400-kcal standardized mixed meal. We sampled serum oxytocin at fasting and at 30, 60, and 120 minutes post-meal. We tested the hypothesis that ARFID would show higher mean oxytocin levels across time points compared to HC using a mixed model ANOVA. We then used multivariate regression analysis to identify the impact of clinical characteristics (sex, age, BMI percentile) on oxytocin levels in individuals with ARFID. Participants with ARFID exhibited greater mean oxytocin levels at all timepoints compared to HC, and these differences remained significant even after controlling for sex and BMI percentile (p = 0.004). Clinical variables (sex, age, and BMI percentile) did not show any impact on fasting and postprandial oxytocin levels among individuals with ARFID. Consistently high oxytocin levels might be involved in low appetite and sensory aversions to food, contributing to food avoidance in individuals with ARFID.