Distorting patient or distorting instrument? Body shape disturbance in patients with anorexia nervosa and bulimia.

Three current techniques for estimating body size (Image Marking, Visual Size Estimation, and Distorting Video techniques) were compared. Anorexia nervosa and bulimic patients and normal control subjects were required to make size judgments of the way they 'knew' they looked, the way they 'felt' they looked, and of the width of an inanimate control object. Results from the three techniques were not the same, thus implying that research findings can no longer be cross-compared. Moreover, while all subjects were similar in the accuracy of their estimation of a control object, anorexia nervosa and bulimic patients overestimated their own body size significantly more than normal controls. This difference was even more marked when affective instructions were compared.