The current study extends earlier observations that body dissatisfaction is positively associated with body weight for eating disorder patients and for nonpatient college women. An adjustment to the Eating Disorder Inventory (E DI) Body Dissatisfaction score (i.e., the "Body Illusion Index" or "BII") is proposed to statistically eliminate the effects of relative body weight on Body Dissatisfaction scores and to systematically increase Body Dissatisfaction scores at lower relative weights. The adjustment results in a mean adjusted body dissatisfaction score for the anorexia nervosa patients more closely resembling that for bulimia nervosa patients and differing significantly from normal weight college women. The "Body Illusion Index'' addresses the different meanings and clinical significance that body dissatisfaction implies for individuals at different weights.0 1992 john Wiley & Sons, Inc.
Attitudinal disturbances such as extreme body dissatisfaction and overconcern with weight and shape have proven to be useful constructs in both the understanding and the treatment of eating disorders. They have intuitive appeal since, on a very basic level, they help to explain the substantial numbers of young women who use harmful weight control behaviors such as self-induced vomiting, with a subgroup of these manifesting serious eating disorders (Fairburn & Cooper, 1982; Killen et al., 1987; Pyle, Halvorson, Neuman, & Mitchell, 1986). The consensus that these attitudes are central features of eating disorders has led to their incorporation into existing diagnostic criteria for both anorexia nervosa and bulimia nervosa by the American Psychiatric Association (APA, 1987). It has also resulted in the proliferation of questionnaires, interviews, and other operational measures, each with their respective merits and limitations (cf. Cash &