Women with sizeable fat in their thighs and buttocks give birth to smarter babies as compared to flat-bottomed women, a new study suggested.Professors William Lassek and Steven Gaulin from the University of Pittsburgh believe the development of a baby’s brain relies on the supplies of fat held in its mother’s thighs and buttocks.Lassek during an interview with the Sunday Times explained having extra fat in the lower part of the body allows a woman to store additional nutrients that can be passed to the baby through breastfeeding.The findings are published in Lassek's recent book“You need lots of fat to make a nervous system and the fats in these areas are also enriched in DHA (docosahexaenoic acid) which is a particularly important component in the human brain.”“It looks as if women have evolved to accumulate these fats and hold on to them — until a baby arrives,” the professor added.Such fat is the hardest of all to shift by dieting. But Lassek said that the ability of women to retain large fat reserves on legs and buttocks was a vital element in the evolution of intelligence.“The fat in these areas is a depot for building a baby’s brain,” the professor added.Lassek pointed out that in most mammals, levels of fat in the body are around 5- to10 per cent, but in women this number rises to 30 per cent.David Bainbridge, a professor at Cambridge University, has backed up these findings in his new book“Women with larger thighs have higher levels of these lipids. There is even evidence that they and their children are more intelligent as a result," Bainbridge said.