USE OF PERCENTILES FOR THE BODY-MASS INDEX IN ANOREXIA-NERVOSA - DIAGNOSTIC, EPIDEMIOLOGIC, AND THERAPEUTIC CONSIDERATIONS

Objective: Percentiles for the body mass index (BMI) offer a possibili ty to epidemiologically assess the linear weight criterion of 85% aver age body weight commonly used for the diagnosis of anorexia nervosa. M ethod: BMI values corresponding to 85% average body weight were calcul ated and assessed with percentiles derived from epidemiological studie s in both the United States and Germany. The underweight range was cha racterized epidemiologically. Results: The weight criterion used for t he diagnosis of anorexia nervosa corresponds to BMI values between the 5th and 10th centiles in both populations. In epidemiological terms t he lowest BMI values in individuals aged 10 years and older occur duri ng adolescence. In the general population BMI values <16 kg/m(2) are r arely observed. Upon the use of higher BMI cutoffs in the underweight range females clearly predominate. The BMI increase associated with th e 5th or 70th centile in the age range between 18 and 30 years is quit e low suggesting that many underweight females in the general populati on gain only minimal weight during this age span. Discussion: The diag nostic, epidemiological, and therapeutic implications for anorexia ner vosa are discussed. (C) 1996 by John Wiley & Sons, Inc.