Clarity is vital: while we know that sedentary lifestyles and excess calories are to blame, these do not explain, on their own, why women are becoming much fatter than men in African countries. As I looked into this I discovered that women are battling a ‘perfect storm’ of cultural, economic and biological forces driving them towards obesity.
I spoke to Moji Musa, a researcher at the centre, which is hosted by South Africa’s Medical Research Council and the University of the Witwatersrand. She told me the gender disparity is “shocking”.
In South Africa in 2013 some 69 per cent of women were overweight or obese: that is a rise of ten percentage points since 1980, compared with just three percentage points for men (male obesity is now 39 per cent), according to a study in The Lancet. Many other sub-Saharan African countries show similar disparities and trends. In Gabon, for example, being overweight afflicts 60 per cent of women, up from 15 per cent in 1980 — compared with 42 per cent of men, up from 10 per cent in 1980.
Globally, however, there was a one per cent difference between male and female obesity in 1980 — and this is still true today.
Musa highlights a cultural difference: in many African counties, women must be big to seem beautiful, fertile, prosperous and free from HIV or tuberculosis.
“A lot of women believe that bigger is better,” explains Musa. “If they try to lose weight they are breaking social conventions.”
She points to research in a Cape Town township. Women there coveted a shape that lies on the border between overweight and obese (at a body mass index, or BMI, of just below 30). Men wanted to be on the normal-overweight border (BMI of 25).
As well as culture, there is economics. The Cape Town study spotted that, while a man’s rising income did not affect his waistline, women bringing in more money grew fatter. Perhaps the real economic influence here is who controls the household food budget.
But culture and economics doesn’t explain it all. The Cape Town research also discovered that having gone hungry as a child was linked to being obese as an adult — again only for women. Researchers think a hungry girl may grow up biologically primed to store fat when she can.
“Combined with the culture I believe it’s a sort of double whammy,” says Musa.
She highlights the need to steer women’s thinking towards healthier values. “The first thing we want to address is this mindset but it’s very, very difficult to do. I think that nutritional and health education is key.”
Aisling Irwin is a science journalist and writer based in the UK, and a former SciDev.Net news editor.