Upper-body fat has negative effects and lower-body fat has positive effects on the supply of long-chain polyunsaturated fatty acids that are essential for neurodevelopment. Thus, waist-hip ratio (WHR), a useful proxy for the ratio of upper-body fat to lower-body fat, should predict cognitive ability in women and their offspring. Moreover, because teenage mothers and their children compete for these resources, their cognitive development should be compromised, but less so for mothers with lower WHRs. These predictions are supported by data from the Third National Health and Nutrition Examination Survey. Controlling for other correlates of cognitive ability, women with lower WHRs and their children have significantly higher cognitive test scores, and teenage mothers with lower WHRs and their children are protected from cognitive decrements associated with teen births. These findings support the idea that WHR reflects the availability of neurodevelopmental resources and thus offer a new explanation for men's preference for low WHR.
They suspect the omega-3 fatty acids in particular as beneficial. So women should eat salmon while pregnant and while nursing.
The answer could be encountered in omega-3 fatty acids, stored in the hips and thighs and which make a large percentage of the human brain. This type of fatty acids is stored by the female body below the waist with the installation of the puberty.
"Men respond because it's reproductively important," Lassek says.
This is not the only evolutionary reason why men prefer curvier women. Women With Hourglass Bodies Have More Reproductive Hormones.
What I wonder: Does the draining of omega 3 fatty acids from a woman in the last trimester of pregnancy contribute to post-partum depression? Check out some of the evidence on omega 3 fatty acids and depression here and here and here.
Also see my post Higher Fish Diet Seems To Make Babies Smarter.
Update: In fact, Joseph R. Hibbeln of the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, has found evidence that postpartum depression is more common among women with lower omega 3 fatty acids (PDF format).
The new study is an analysis of 11,721 British women. Researchers found that the more omega-3 fatty acids a woman consumed in seafood during the third trimester, the less likely she was to show signs of major depression at that time and for up to eight months after the birth.
In fact, the rate of depression in the women with the highest intakes was only about half that of women with the lowest intakes, says senior author and psychiatrist Dr. Joseph R. Hibbeln.
Omega 3 fatty acids is one of the two nutrients most people should try to get more of. Vitamin D is the other one. Go for salmon and sardines to get more omega 3 fatty acids. It'll even reduce the chances you'll commit a crime.
|Share |||Randall Parker, 2007 November 10 09:40 AM Brain Development|