BODY PERCEPTION INDEX - BENEFITS, PITFALLS, IDEAS

Estimates of body size are often expressed as a ratio of actual size [ body perception index or BPI=(estimated size/actual size)x100%]. In th is article, we examine the possibility that overestimation of body siz e in patients with anorexia nervosa, as measured by the BPI, is due to their smaller body size rather than to their being anorexic. Using 50 mean body sizes derived from seven studies we investigated whether th e error of estimation is a constant proportion of the body size to be estimated, as the use of the BPI assumes. A negative linear relation b etween BPI and actual body size was found, confirming that smaller siz e is associated with greater overestimation. However, although both gr oups showed a strong tendency to overestimate smaller sizes, anorexic subjects showed even greater overestimation than controls. Hence, over estimation of body size in AN can only partially be accounted for by t he smaller body size of anorexic patients. Recommendations for future use of the BPI are put forward. (C) 1998 Elsevier Science Inc.