It’s a Man’s World?


In a recent post I looked at the change in body mass index (BMI) of men compared to women across the globe. BMI is a ratio based on a person’s weight relative to their height, so for a given height, skinnier people tend to have lower values and heavier people tend to have higher values.

In some sense, I think BMI could be useful as metric of the well-being of a population. In times of war and economic downturn, BMIs tend to drop (or rise more slowly than otherwise). And, men and women are not necessarily equally affected. For example, in the 1997 economic crisis in South Korea, women were noticably affected for several years, while men didn’t seem to be affected at all.

I made a scatterplot that showed that in most countries of the world from 2007 to 2008, both men and women increased their BMIs slightly, even in Afghanistan and Zimbabwe and other unsavory places.

(click image to enlarge)

In fact, Afghanistan’s women gained BMI (as a year-over-year percentage) more than men did. My assertion was that, from a BMI perspective, Afghanistan is actually a female-biased place. Sure, the women there in general lead terrible lives. But so do the men. Men beat and abuse and torture and kill women. But they do that to other men, too. And the BMI numbers seem to show that men and boys are faring worse than the women.

In the last 28 years, women lost BMI in Afghanistan in ten of them – 1989 through 1996, and in 2001. They have gained each year since 2002. But men lost BMI in 24 of those 28 years, gaining only since 2005. If a man wants lots of young male allies when he’s old, he needs to take care of his wife/wives, daughters and nieces.

The map below shows data from that scatterplot, with each country colored according to the difference in mens’ and womens’ BMI change from 1980 to 2008.

(click image to enlarge)

So, Brazilian men in 1980 had an average BMI of 22.64 and in 2008 it was 25.79. Thus, Brazil’s men increased their BMIs, on average, by 13.9% in that time period. Brazilian women, in contrast, increased from 24.05 to 26.0, or 8.1%. Thus, Brazilian men benefitted a little more in the waistline than women did. Subtracting the two gives a 5.8% difference, which is why Brazil is colored a medium shade of blue on my map.

By this system, blue values indicate that men gained BMI more (or lost less) than women, red values indicate women gained more (or lost less) than men, and values near zero mean that both men and women gained or lost equally.

There’s some stuff in this map that is reassuring and a lot that I find surprising. The Nordic countries, for example.

  • Norway and Denmark are right in the middle of the road (no surprise there), but Sweden is male-biased while Finland is female-biased. In fact, Finland, Estonia and Moldova are the only European countries with female biases – in all of the rest men gained BMI more than women.
  • The former Communist countries of the Eastern Bloc are slightly more male-biased than Western Europe (again, no surprise).
  • As with much else in life, when it comes to BMI equity, the UK is unlike most of the rest of Europe.
  • All of North America is female-biased. I hadn’t expected that. Canada is a little more feminine than the US (no surprise), but the contrast between North America and Europe is astonishing.
  • It’s puzzling to me that in both India and China women gained BMI more than men since 1980. Both of these countries have problems with sex selection – baby boys outnumber baby girls. I guess that their attitude is: we prefer for sons to be born, but we feed our daughters better.

I’ve also looked at other time frames, including various 5-year periods and the general results are the same. So, I don’t think there’s anything particular about 1980-2008.


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