A distorted body image is thought to play a part in anorexia and bulimia. Researchers from the Medical University in Berlin compared 129 teenage girls with eating disorders to a control group of 354 girls of a similar age. The two groups were asked to indicate what they thought the circumference of their arms, thighs and waists were, then measured to see what their actual dimensions were. The control group overestimated their body circumferences by 8-16% whereas the participants with eating disorders overestimated their body circumferences by 30%. The biggest difference in estimates were between the estimates for thigh and waist circumference. There was no significant difference in the degree of overestimation between the participants with anorexia and those with bulimia.
Schneider, Nora ... [et al] - Comparison of body size estimation in adolescents with different types of eating disorders European Eating Disorders Review November-December 2009, 17(6), 468-475