Ben Hirschler
Women on low-calorie diets or who skip breakfast at the time of conception are more likely to give birth to girls, UK scientists say.
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 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,” says Dr Fiona Mathews of the University of Exeter.
The latest findings are published in the journal Proceedings of the Royal Society B: Biological Sciences.
There has been a small but consistent decline, of about one per 1000 births annually, in the proportion of boys being born in industrialised countries over the past 40 years.
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.