Is there a basis for a weight cut‐off point? A large‐scale investigation of atypical anorexia and anorexia nervosa subtypes among patients at a residential treatment centre

Objective There is debate surrounding how to differentiate between anorexia nervosa (AN) and atypical AN (atypAN) as diagnostic entities, and whether a distinction based on BMI is warranted. Better understanding eating disorder (ED) and emotional symptoms across atypAN and AN subtypes [AN‐restricting (AN‐R), AN‐binge/purge (AN‐BP)], with and without controlling for BMI, can elucidate how atypAN differs from AN subtypes and whether there is a basis for a BMI cut‐off. Methods 1810 female patients at an ED treatment centre completed intake surveys. ANCOVAs assessed differences across AN‐R (n = 853), AN‐BP (n = 726), and atypAN (n = 231) groups on ED, depressive, and anxiety symptoms, anxiety sensitivity, experiential avoidance, and mindfulness, with and without controlling for BMI. Results Relative to AN‐R, atypAN and AN‐BP groups endorsed significantly higher ED and depressive symptoms, anxiety sensitivity, experiential avoidance, and significantly lower mindfulness (all p