Nigella Lawson: Curvy figure and an Oxford degree

Researchers studied 16,000 women and girls and found the more voluptuous performed better on cognitive tests - as did their children.

The bigger the difference between a woman's waist and hips the better.

Researchers writing in Evolution and Human Behaviour speculated this was to do with fatty acids found on the hips.

In this area, the fat is likely to be the much touted Omega-3, which could improve the woman's own mental abilities as well as those of her child during pregnancy.

Men respond to the double enticement of both an intelligent partner and an intelligent child, the researchers at the Universities of Pittsburgh and California said.

The findings appear to be borne out in the educational attainments of at least one of the UK's most famous curvaceous women, Nigella Lawson, who graduated from Oxford.

But experts are not convinced by the findings.

"On the fatty deposits being related to intelligence front, it's very hard to detangle that from other factors, such as social class, for instance, or diet," said Martin Tovee of Newcastle University.

"And much as we logically like the idea that men are interested in the waist to hip ratio, it actually features relatively low down the list of feature males look for in a potential partner."