Anorexic women are most likely to be born in the spring or early summer, a study by a consultant psychiatrist claims.

The research suggests that a seasonal factor, such as a winter cold or influenza during pregnancy, may predispose an unborn baby to the eating disorder, Dr John Eagles said.

The consultant, who works at the Royal Cornhill Hospital in Aberdeen, made the link after comparing 446 anorexic women with healthy women. But his theory was dismissed yesterday as "probably meaningless" by another specialist.

According to a report published yesterday in New Scientist, Dr Eagles found more women born in the first half of the year developed anorexia than those born in the second half. From March to June, there were 13 per cent more anorexics born than average, and 30 per cent more in June alone.

Anorexia was first thought to be a psychological disorder triggered by a stressful family life or a weight-obsessed culture. But Dr Eagles said biological or genetic factors could be involved, which may include winter illnesses. However, he admitted: "It's not the whole answer."

His team compared women diagnosed as anorexic or who had suffered symptoms between 1965 and 1997 with 5,766 women with no history of anorexia but who were born in the same area of Scotland.

Dr Eagles said there was a precedent for the theory. Schizophrenics are more likely to be born in the first four months of the year, with studies linking it with influenza or polio infecting patients' mothers in the second three months of pregnancy.

But Dr Blake Woodside, a psychiatrist at the University of Toronto, said the seasonal link was "not particularly powerful and probably meaningless". He said anorexia was probably caused by a mix of genes, environment and temperament.