Patients with anorexia have trouble accurately judging their own body size, but not others', according to research published Aug. 22 in the open access journal PLOS ONE.

In the study, led by Dewi Guardia of the University Hospital of Lille in France, 25 patients with anorexia and 25 controls were shown a door-like aperture and asked to judge whether or not it was wide enough for them to pass through, or for another person present in the room to pass through.

In previous similar experiments, anorexic patients felt they could not pass through the door even when it was easily wide enough, and in the current study, the researchers found that the anorexic patients were more accurate at judging others' ability to pass through the aperture than their own. They also found a correlation between the perception of their own ability to pass through the aperture and their body size prior to becoming anorexic, suggesting that the patients may still think of themselves as their previous size.