The Daily—you remember, Rupert Murdoch’s iPad newspaper—had a cool angle today on a study of global obesity, focusing on shares of total global weight. Unfortunately, they got the math embarrassingly wrong:
Asia is home to 61 percent of the world’s population but just 13 percent of its weight.
Er, let’s imagine that we’ve led the entire population of the Asian continent onto one tray of the world’s largest, most macabre butcher scale. Does The Daily really want us to think that if we just placed one out of every seven people remaining on the planet onto the other half of the scale, the thing would balance? This would mean that the average Asian weighs one-tenth of everyone else’s average. That’s obviously not right. Oh, how convenient, a table:
Try to ignore the almost cannibalistic ghoulishness that is thinking about fractions of people per ton. (“How many Eritreans in that ton you sent me?” “Nineteen and a leg.”) Focus on the data.
It turns out that the heaviest people, Americans, weigh about two-thirds more than the lightest people, Bengalis, who weigh on average just under a hundred pounds apiece. So The Daily’s wrong about Asian weight. The Daily’s also wrong when it says that North America has over a third of global weight: we’d need about three times our population to be there. Let’s also note that many of these skinnier countries are, you know, places I’m glad I’m not a citizen of. The data shows what the piece ignores: for the time being, hunger remains a bigger global issue than obesity.
At least the donut globe illustration was nice.
UPDATE: I found the study’s press release here. The relevant paragraphs:
Using data from the United Nations and World Health Organization, researchers from the London School of Hygiene and Tropical Medicine estimated that the adult human population weights in at 287 million tonnes. 15 millions of which is due to the overweight and 3.5 million due to obesity.
While the average body mass globally was 62kg, North America, which has the highest body mass of any continent, with an average body mass of 80.7kg. North America has only 6% of the world’s population but 34% of the world’s biomass mass due to obesity. In contrast Asia has 61% of the world’s population but only 13% of the world’s biomass due to obesity.
The report’s infelicitous metric “biomass mass due to obesity” means that there’s 3.5 million tonnes of “biomass” attached to people globally what wouldn’t be there if they weren’t obese. 34% of that 3.5 million tonnes is attached to North Americans. Only 13% is attached to Asians. Let’s also note that The Daily changed tonnes to tons, so that the average Bengali actually weighs a little more than 100 pounds.