Melbourne: Scientists have developed a new approach for diagnosing patients with anorexia nervosa, an eating disorder, which they claim could have a significant impact on the treatment and recovery of sufferers.

A team at the University of Sydney, led by Prof Stephen Touyz, has advocated a move to diagnosing anorexia nervosa in stages of severity, similar to the method used for diagnosing cancer, the 'Sydney Morning Herald' reported.

"At the moment, you can only diagnose anorexia nervosa if you have the illness quite severely already. By the time you have anorexia nervosa, and people can see that you've got it, you're an extremely ill person. This is an illness where 20 percent of people who are diagnosed could potentially die," Prof Touyz said.

The proposed system of stages would introduce the diagnosis of stage one anorexia nervosa for patients who clearly already suffer from the illness but do not yet meet its official diagnostic criteria, say the scientists.

The need for early diagnosis and treatment is particularly pressing given the severe lack of hospital treatment options for adults suffering from anorexia nervosa.

"But if you pick up the disease early enough, you can receive proper treatment early on, have a better chance of overcoming the illness and avoid hospitalisation," Professor Touyz said. The staging would also improve public awareness and understanding of anorexia nervosa, say the scientists.

"People who have symptoms of anorexia nervosa but don't meet the diagnostic criteria are currently described as having EDNOS, or 'eating disorder not otherwise specified'. If you tell people you have EDNOS, few people understand. But if you say you have stage one anorexia nervosa, people appreciate the seriousness of the condition," he said.