By IANS
London : Researchers have stumbled upon evidence that clearly establishes a link between a child’s gender and the mother’s high-energy diet.
The findings may help explain the falling birth rate of boys in highly industrialised countries like the US and Britain.
The study focused on 740 first-time pregnant women in Britain, who did not know the sex of their foetus. They were asked to provide records of their eating habits before and during early stages of pregnancy.
They were then split into three groups according to the number of calories consumed daily around conception. Fifty-six percent in the group with the highest energy intake had sons, compared with 45 percent in the lowest group.
As well as consuming more calories, women who had sons were more likely to have eaten a higher quantity and wider range of nutrients, including potassium, calcium and vitamins C, E and B12. There was also a strong correlation between women eating breakfast cereals and producing sons.
Over the last 40 years there has been a small but consistent decline, of about one per 1,000 births annually, in the proportion of boys being born in industrialised countries, including Britain, the US and Canada.
Previous research has also shown a reduction in the average energy intake in the developed world. The ‘obesity epidemic’ is largely ascribed to decline in physical activity and differences in food quality and eating habits.
There is also evidence that skipping breakfast is now common in the developed world: in the US, the proportion of adults eating breakfast fell from 86 percent to 75 percent between 1965 and 1991.
Fiona Mathews of the University of Exeter, co-author on the paper, said: “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.”
The mechanism is not yet understood, but it is known from in-vitro fertilisation (IVF) research that high levels of glucose encourage the growth and development of male embryos while inhibiting female embryos.
In humans, skipping breakfast depresses glucose levels and so may be interpreted by the body as indicating poor environmental conditions and low food availability.
This research appeared Wednesday in Proceedings of the Royal Society B: Biological Sciences.