Table 1.

Diagnostic criteria, subtypes and severity of anorexia nervosa

Diagnostic variable
Diagnostic criteria	(1) Restriction of energy intake relative to requirements in anorexia nervosa leads to significantly low body weight for the patient´s age, sex, developmental trajectory and physical health. Significantly low weight is defined as a weight that is less than the minimal normal weight or (in children and adolescents) less than the minimum expected weight; (2) Intense fear of gaining weight or of becoming fat, or persistent behaviour that interferes with weight gain, even though the patient has a significantly low weight; and (3) Disturbance in the way in which one´s body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or persistent lack of recognition of the seriousness of the current low body weight
Subtype designation	Restricting subtype: During the past 3 mo, the patient has not engaged in recurrent episodes of binge-eating or purging behaviour (i.e. self-induced vomiting or the misuse of laxatives, diuretics or enemas). Weight loss is primarily through dieting, fasting or excessive exercise, or all of these methods; Binge-eating/purging subtype: During the past 3 mo, the patient has engaged in recurrent episodes of binge-eating or purging behaviour (i.e., self-induced vomiting or the misuse of laxatives, diuretics or enemas)
Current severity	Mildly severe low body weight is defined as BMI > 17.00 kg/m2; Moderately severe low body weight is defined as a BMI of 16.00-16.99 kg/m2; Severe low body weight is defined as a BMI of 15.00-15.99 kg/m2; Extremely severe low body weight is defined as BMI < 15.00 kg/m2[1,2]

All three diagnostic criteria are required for the diagnosis anorexia nervosa. BMI: Body mass index.