A new report, produced at the University Hospital of Lille, has concluded that patients with anorexia are often oblivious to how thin they actually are.
The research team in France used an innovative approach to discover how self-aware anorexia patients are about their own body size.
To achieve this, the research team used a projector to display the outlines of doors of different sizes of wall and then ask people with the eating disorder to say whether they would be able to fit through the space.
Subsequently, the patients were asked whether someone standing nearby would be able to fit themselves through the same space.
The study, published in the journal PLOS ONE, said that the patients were only able to answer correctly when they were determining if someone else could fit through the space.
"I think it's really fabulous that these researchers are able to provide scientific proof of what people who have worked with these patients have known for a very long time," explained Dr Elizabeth Frenkel, a supervising psychologist at the Princeton HealthCare System's eating disorder program.
"They're trying to demonstrate that you can show a clinical and statistically significant difference between people who have these disorders and people who don't."
Meanwhile, Phillip Levindowsky, a psychology professor at Harvard Medical School, observed that people with eating disorders often struggle to form rational opinions about their appearance.
An obsession about their weight often leads people with such problems to struggle to make sound judgments.
"It is an interesting study using interesting methodology that gives us directions for future research to further clarify the process of what is happening during these evaluations," she told ABC news.
Recently, Joseph Petri, of the Delray Recovery Center, said that people with eating disorders must be totally honest about their problems if they are to be overcome.
He observed that in many instances, people with anorexia and other similar problems are reluctant to discuss such issues with their loved ones.