[Anorexia nervosa--the triad of metric index, BMI age-specific percentile curve and goal weight]. / Anorexia nervosa--Die Trias von Metrik-Index, BMI-Altersperzentilenkurve und Zielgewicht.

Cross sectional and longitudinal data from the Berlin Anorexia Study on the inpatient treatment of n = 133 adolescent females with the principal axis I diagnosis of an eating disorder (n = 104 anorexia nervosa, n = 19 bulimia nervosa, n = 10 eating disorders not otherwise specified; according to ICD-10 and DSM-IV criteria) indicate a significant shift in the frequency distribution of somatometrically assessed types of body shape among patients as categorized by the Metric Index, towards the leptomorphic phenotype (p < 0.050, chi 2/Fisher's). Three explanatory models are discussed. Diagnostic and therapeutic implications, particularly of the determination of target weight in anorexia nervosa based on the individual's type of body shape, are emphasized, and an operational algorithm is proposed which uses the Metric Index and sex-specific BMI age percentiles adjusted for type of body shape.