Women on low-calorie diets more likely to have girls

London: Women on low-calorie diets or who skip breakfast at the time of conception are more likely to give birth to girls than boys, British scientists said yesterday.

New research by the universities of Exeter and Oxford provides the first evidence that a child's sex is associated with the mother's diet, and that higher energy intake is linked to males.

"This research may help to explain why in developed countries, where many young women choose to have low-calorie diets, the proportion of boys born is falling," said Fiona Mathews of the University of Exeter.

In humans, going without breakfast may be interpreted by the body as signalling low food availability, since it depresses levels of blood sugar.

Although sex is genetically determined by fathers, it is known that high levels of glucose encourage the growth and development of male embryos while inhibiting female ones.

Mathews and colleagues studied 740 first-time pregnant mothers in Britain and found 56 per cent of those in the group with the highest energy intake at conception had sons, compared with 45 per cent in the lowest group.

The findings were published in the journal Proceedings of the Royal Society B: Biological Sciences.