Examining Diagnostic Criteria for Atypical Anorexia Nervosa Post Metabolic Bariatric Surgery.

OBJECTIVE: To examine the applicability of current diagnostic criteria for atypical anorexia nervosa (AAN) to patients 1 year post Metabolic Bariatric Surgery (MBS). METHOD: This prospective ongoing cohort study included patients from the multicenter Psychosocial Registry of Obesity Surgery assessed before surgery and 1 year-post-MBS. From a consecutive sample of 1117 volunteers with planned MBS, 985 received surgery, 721 had the 1 year-post-MBS assessment and were eligible for the study. DSM-5 criteria for AAN 1 year-post-MBS were assessed using diagnostic items of the Eating Disorder Examination (EDE) interview. Main outcomes were percentage of total weight loss (%TWL), body mass index (BMI) 1 year-post-MBS, and eating disorder (ED) psychopathology (EDE questionnaire; pre- and 1 year-post-MBS). RESULTS: Of the 721 patients [490 (66.7%) female; mean(SD) age 46.72 (11.52)], 65.6% (n = 469) reported EDE item "Maintained low weight" (DSM-5 Criterion A), and 61.1% (n = 440) reported "Importance of shape and/or weight" (Criterion C). EDE item "Dietary restriction" (Criterion A) and "Fear of weight gain" (Criterion B) were reported by 4.1% (n = 29) and 4.6% (n = 33) of patients, respectively. Only 1.8% (n = 13) engaged in "Extreme weight control behaviors" (Criterion B). Following a DSM-5-based coding scheme, 3.9% (95% CI. 2.7-5.6; n = 28) of patients had AAN 1 year-post-MBS. AAN and non-EDs patients did not differ on %TWL/BMI. All EDE diagnostic items, except "Dietary restriction," significantly explained ED psychopathology (F(7,586) = 28.97, p < 0.001, R2 = 0.26) with "Fear of weight gain" and "Extreme weight control behaviors" being associated with the highest variance explained. CONCLUSION: While BMI and %TWL did not distinguish AAN from non-ED, "Fear of weight gain" and "Extreme weight control behaviors" may be a better indicator of these problems among patients 1 year-post-MBS.