Clinical Phenotypes and Neurobiology of Youth With Avoidant/Restrictive Food Intake Disorder ( ARFID ) Across Sex

OBJECTIVE: Avoidant/restrictive food intake disorder (ARFID) is an eating disorder characterized by persistent avoidant/restrictive eating unrelated to body image. Sex differences in clinical phenotypes and neurobiology of ARFID are understudied. We hypothesized that females with ARFID would have a greater frequency of the lack of interest and fear of aversive consequences phenotypes, higher levels of anorexigenic hormones, and greater fMRI activation in brain regions associated with cognitive control during a food cue paradigm. We further hypothesized that males with ARFID would have a greater frequency of the sensory sensitivity profile, higher levels of orexigenic hormones, and greater fMRI activation in reward processing brain regions. METHOD: We recruited 96 children and adolescents with ARFID and sub-threshold ARFID (49% female) from two studies on the neurobiology of ARFID and low weight eating disorders from 2016 to 2022. We analyzed ARFID clinical phenotypes; appetite-regulating hormones, ghrelin, cholecystokinin (CCK), peptide YY (PYY), and oxytocin; and fMRI activation of cognitive control and reward-related brain regions during a food cue paradigm using frequentist and Bayesian statistical analysis. RESULTS: Contrary to our hypothesis, there were no sex differences in frequency of ARFID clinical phenotypes, appetite-regulating hormone levels, or brain activation. CONCLUSIONS: This is the first study to provide empirical evidence that ARFID has a similar clinical and neurobiological presentation in males and females.