Western images of super-thin models and actresses are leading to the first cases of eating disorders in the most rural and deprived parts of South Africa.

Young black women are rejecting traditional beliefs that "big is beautiful'' and starving themselves on the model of the waif-like idols they see on television, film and in magazines. Consequently, cases of anorexia and bulimia are now emerging in Zululand in rural South Africa, a study by psychologists at Northumbria University found.

Researchers found that among 21 female students at the University of Zululand, 45 per cent showed the behavioural signs of eating disorders, such as fasting or making themselves sick. In a random sample of 21 female students from Northumbria University, 25 per cent showed similar signs.

Julie Seed, the senior lecturer in psychology at the university and author of the studies, said: "The most common reason given by the South African women was that they are following the western ideal of thinness equals beauty, because they think that is how men want them to look now.

"A number of women explicitly stated that they wanted to look like the women on television and in magazines. They equate thinness with progress and being modern. Traditional Zulu outfits are designed to fit all, but there is the impression that, in wearing these, they will appear old-fashioned.''

Ms Seed said that many of the South African women believed male perceptions had been influence by Western images. One student said that larger Zulu women were once called "queens'' as a term of admiration for their attractive body size. Now the word queen was used as a term of derision to tease larger women.

Ms Seed said: "There is often a conflict for these young women. At university, they feel pressure to be thin and think that is what will make them attractive.

"But when they go home to their families in the country they are often told that they need to put on weight and there are fears that, if they look too thin, people will think they have Aids. This conflict can be especially dangerous because it is associated with a risk of eating disorders.''

But the desire to be thin may come from beneficial cultural change in areas such as Zululand. Ms Seed said: "Thinness is also associated with empowerment.

"Once these women didn't have a choice over their body shape because being fat was associated with wealth and so their fathers told them they had to put on weight. Now they are more independent, they feel that it is up to them what weight they want to be and that being thin shows they have control over their lives.''