Use of percentiles for the body mass index in anorexia nervosa: Diagnostic, epidemiological, and therapeutic considerations

Objective Percentiles for the body mass index (BMI) offer a possibility to epidemiologically assess the linear weight criterion of 85% average body weight commonly used for the diagnosis of anorexia nervosa. Method: BMI values corresponding to 85% average body weight were calculated and assessed with percentiles derived from epidemiological studies in both the United States and Germany. The underweight range was characterized epidemiologically. Results: The weight criterion used for the diagnosis of anorexia nervosa corresponds to BMI values between the 5th and 10th centiles in both populations. In epidemiological terms the lowest BMI values in individuals aged 10 years and older occur during adolescence. In the general population BMI values