Body weight is crucial to eating disorders. Beyond gender, age, and height it is determined by anthropometric features of physique, i. e. somatotypes. We investigated their impact on the anthropometric and metabolic assessment of nutritional status, psychometrics, and other clinical aspects of eating disorders. In 133 eating disordered girls (ICD-10 & DSM-IV criteria) of well-recorded catamneses, various somatometric measures (n = 133), serum leptin (n = 30), plasma tryptophan (n = 108), and psychometric scales (n = 119; EDI-64 & EAT-40) were examined, preferably on repeated occasions of their treatment and in comparison to 41 healthy controls. Somatotyping was performed by gender- and age-specific quintiles of Strömgren's Metrik Index (MI) derived from 6995 volunteers constituting the anthropometric reference.Somatotypes represent a significant factor for assessing nutritional status. Exhibiting higher EDI-64 bulimia ratings at admission, more prevalent self-induced vomiting and purgative substance abuse as well as prolonged refractory illnesses with more previous inpatient treatment trials but later admissions, heavier somatotypes were significantly underrepresented in our total clinical sample but more prevalent among bulimic eating disorders (p < 0.05). Neglecting the anthropometry of physique biases against the detection and treatment of eating disorders in heavier somatotypes at weights below general average. Henceforth, this shall be avoided by somatotyping according to frame indices.