Weight outcomes for adolescents with atypical anorexia nervosa in family-based treatment

Background: Although over one-third of adolescents presenting with restrictive eating disorders have a history of being overweight, there is no evidence-based treatment for atypical anorexia nervosa (AAN). Family-Based Treatment (FBT) is a feasible treatment and is routinely applied to treat atypical anorexia nervosa in adolescents; however, identifying a treatment target weight within FBT for these patients is a challenge. Objective: This study aimed to 1) increase understanding regarding recommendations for weight gain versus weight stabilization in FBT for adolescents with AAN and 2) examine treatment outcomes in FBT for adolescents with AAN. Method: Using a retrospective design, we reviewed the files of 41 patients with AAN who were referred for FBT at a pediatric eating disorder program located within a tertiary care health centre. Results: We found variability in recommendations for weight gain, with 56% of the sample recommended to gain weight and 44% recommended to stabilize weight. Baseline BMI for age appeared to be a key factor in establishing recommendations for weight gain. AAN patients in our sample gained a significant amount of weight across treatment, with those recommended to gain weight showing more weight gain during treatment. Forty-nine percent of the sample completed FBT; those patients displayed a mean of 10kg of weight gain during treatment. Conclusions: Findings suggest that many patients gained weight during the course of FBT for AAN. Further study on weight changes during FBT for adolescents with AAN and increased diagnostic consistency for AAN will be important for this field.