Urgent action is needed to identify children suffering from eating disorders which have a death rate similar to childhood leukaemia, medical experts say. Anorexia and bulimia are traditionally seen as a problems of adolescence but evidence suggests they are starting earlier in childhood.

Prompt treatment is essential to tackle what can develop into a long-term serious disorder, researchers from the Insititute of Child Health in London say. On average children wait eight months to see a specialist with up to half requiring hospital admission and one in seven feeding by tube into their stomach.

About three in every 100,000 children under the age of 13 are affected, according to the first survey of early onset eating disorders published in the British Journal of Psychiatry. The study identified 208 children aged from six to 13 with the diagnosis over a 14 month period from March 2005 to May 2006.

The most common symptom was a determined refusal of food. Parents described their children as "fussy eaters", refusing anything except milk or liquids, "intolerant of lumps" and "not aware of hunger".

Charlotte Bevan's daughter Georgie, 12, developed anorexia two years ago while away at boarding school. After hospital treatment i, her mother instituted a "re-feeding" scheme she learnt about on the web. "I fed her six times a day for a year. I didn't persuade her, I required her to eat. The mantra in this house was the food is your medicine. We were very kind but very firm. If she didn't eat we sat there until she did eat.

"If your daughter had cancer and said the chemotherapy was painful, could she stop, you would have said no, because she would die. That's what we were facing. I was petrified she would die."

Georgie grew 5ins in a year, transferred to a local day school and is now fine, her mother said.

Dasha Nicholls, consultant child and adolescent psychiatrist at University College Hospital who led the study, said: "Typically the problem begins with increasingly rigid eating behaviour - the child starts cutting out certain foods. Then, as it becomes more entrenched you get arguments over food.

"It is difficult for parents to know whether to take it seriously because it is quite normal for children to express their feelings through food and many have difficulties. The key point is preventing it getting established. We would like parents and professionals to take it more seriously. If you are told someone's child has leukaemia you don't have a problem taking it seriously even though it has a 90 per cent recovery rate."