Children as young as six have suffered signs of eating disorders, according to a study of the under-13s. Figures from the British Paediatric Surveillance Unit show that 206 cases were reported over a 13-month period from March 2005. That equates to 3.5 children for every 100,000.

Of those, 37 per cent were said to have anorexia and 18 per cent of all cases were boys.

The youngest child was 6 and was showing some, but not all, the features of anorexia. The youngest diagnosed case of anorexia was in an 8-year-old. Half of all the children had to be admitted to hospital but 60 per cent have improved.

The study also found that 45 per cent of children exercised excessively to keep their weight down.

The data were collected by members of the Royal Colleges of Paediatrics and Child Health and Psychiatry.

Eating disorders, including anorexia, bulimia and binge eating, are rarely seen in children before puberty, but cases rise steeply in early adolescence in girls, peaking at age 14.

Early developing girls are more likely to have symptoms of an eating disorder than late developers, suggesting that the stage of puberty could be a more important factor than age. The average age at which girls have their first period is now 12½ in most developed countries.

Dasha Nicolls, a lead investigator and child and adolescent psychiatrist at Great Ormond Street Hospital, said: “It is important to understand that an eating disorder is when someone is worried about their weight or shape.

“It is possible to have severe eating difficulties where weight or shape is not driving this.”

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