SINGAPORE - The number of people suffering from eating disorders may be higher than reported in Singapore.

And this, says Dr Lee Huei Yen, Director of the Eating Disorders Programme at the Singapore General Hospital, is because of the strict criteria set for diagnosing bulimia or anorexia. "Bulimia by right, should be bingeing and purging twice a week for at least three months. So maybe sometimes if you do it once a week, strictly, you can't call them bulimic," explained Dr Lee.

As for those with extreme weight loss, she pointed out it could be that their body weight hasn't fallen low enough to meet the diagnostic criteria for anorexia.

Dr Lee said such cases come under the category of people having Ednos - an acronym for an eating disorder not otherwise specified - which applies to people who have eating disorders but don't meet the strict criteria for either anorexia nervosa or bulimia nervosa.

Patients may also be confused as to whether they have eating problems, and doctors may not be able to spot the condition.

"If you go out to Orchard Road and interview 10 women, nine of them will be on some kind of diet. They watch what they eat very carefully, they exercise, and they're concerned about weight and shape. But what makes you different from a person with eating disorder is that it must affect you either physically, socially or emotionally," she said.

Dr Lee said Ednos can be triggered by multiple factors and can be quite severe in some cases, but the condition can be treated although recovery will not come overnight.

"Research has shown that about 30 per cent would have fully recovered, although at the end of 10 years, about 70 per cent would have fully recovered by then. So, the majority get well; it's just a matter of how long they take to get well," she added.