The theory that media images of thin models encourages anorexia among young girls may not be correct, suggest doctors.

A study carried out in rural Africa found that the eating disorder may exist there and may not be a solely 'western' phenomenon.

Doctors from Edinburgh screened all 668 female students at a secondary school in rural Ghana for height and weight to determine if they met the criteria for diagnosing anorexia nervosa.

The girls came from various social backgrounds.They were not poor and had access to food.

However, a small number were found to have low weight caused by self-imposed diets.

The six girls cited various reasons for dieting. These included religious fasting, particularly around times of stress, and for feelings of self-control.

The study follows claims that anorexia nervosa only occurs in the developed world and is a result of media and movie images of thin women.

But Dr Alan Carson, a consultant psychiatrist at the University of Edinburgh, said the findings of the study showed that this may not be the case.

"The girls did not present with symptoms of classical anorexia nervosa but the study does suggest that perhaps it is not confined to the western world.

"It also shows that there may be many reasons why girls develop anorexia and we need to examine this further to see if it goes across cultures and if there is a common approach we can take to tackle it."

The findings will be presented to doctors on Wednesday at the annual meeting of the Royal College of Psychiatrists in Edinburgh.

In June, the government hosted a summit, attended by magazine editors and other media representatives, aimed at addressing the media's role in encouraging anorexia among young girls.

The summit looked at the use of thin models in magazines and newspapers. Some of those present pledged to adhere to voluntary guidelines not to use overly-thin models in their publications and to vary female shapes following the meeting.

Research suggests that more than half of girls are concerned about their appearance and two in three feel inadequate compared with the media image of the ideal female shape.

Only a quarter said they were happy with their weight and 88% said there was pressure from the media to "look perfect".