Inpatient hospital course and self-reported symptomatology in underweight adults with ARFID compared to age- and sex-matched controls with anorexia nervosa

Objective Avoidant restrictive food intake disorder (ARFID) has similar prevalence to anorexia nervosa (AN) in adults, but research in this population is lacking. Although inpatient or residential treatment involving nutritional rehabilitation is increasingly recommended for malnourished individuals with ARFID, best practices remain poorly defined. Existing studies on self-reported symptomatology and treatment course and outcome are primarily in child and adolescent cohorts and demonstrate inconsistent findings. This study aimed to compare hospital course and self-reported symptomatology of underweight adult inpatients with ARFID and sex- and age-matched patients with AN. Method Underweight adult patients with ARFID or AN admitted to a specialized, hospital-based behavioral treatment program completed measures of body dissatisfaction, drive for thinness, bulimic symptoms, anxiety, depression, and personality traits. Demographic and treatment course data were abstracted from electronic medical records. Patients with ARFID ( n = 69) were matched to those with AN ( n = 69) based on sex and age. Results Adults with ARFID were closer to target weight at admission, but gained weight at a slower rate, were discharged at lower BMI, and were less likely to reach target weight by discharge than adults with AN. Patients with ARFID reported less weight and shape-related eating disorder, state anxiety, and depression symptoms and lower neuroticism. Discussion Adults with ARFID progress through treatment more slowly and achieve less favorable weight outcomes by hospital discharge than patients with AN, but long-term outcomes are unclear. Describing clinical presentations and course of illness of adult ARFID may help inform treatment protocols.