Researchers found that women born at least eight weeks prematurely were three times as likely to be treated for anorexia.

They believe it may be due to the extended period of separation from the mother, as well as being fed through a tube.

The study, published in the American Medical Association's Archives of General Psychiatry, followed the progress of 781 females born between 1973 and 1984.

Of this group, 1.8% were treated for anorexia between 1987 and 1994.

But the normal rate for a "control" group born after a normal-length pregnancy is only 0.6%.

Professor Sven Cnattinguis of the Karolinska Institute in Stockholm said: "We found that girls developed very prematurely were three times more likely to develop anorexia which required hospital treatment."

Brain damage

He also hypothesised that premature birth resulted in small brain injuries which affected visual perception and appetite.

Studies by British researchers in 1997 showed that the brains of young girls with anorexia had marked differences, possibly pointing to a biological cause for the eating disorder.

Prof Cnattinguis said: "If this link is true, it will only explain a fraction of anorexia cases.

"What I think is important is that there are many centres which follow the progress of premature infants and hopefully they will also look at eating difficulties."

There is great interest in the subject in Sweden, sparked partly by Sweden's popular Crown Princess Victoria, who has publicly acknowledged her battle against eating disorders.