Obesity isn’t just bad for individual health—or even the larger health care systems—it’s also a strain on the planet. A recent report from the British Medical Council looks at the effect of increased global fatness on world food energy demands—and finds that all those extra pounds could require as much food energy as another half billion people. This in turn could cause food prices to rise. The U.S., of course, is responsible for the bulk of the problem.
The researchers used existing data on body mass index (BMI) and height distribution to estimate average adult body mass, with total biomass calculated as the product of average body mass and population size. They then estimated the percentage of the population of major countries that are overweight or obese, as well as their average body mass. What they found is disturbing: in 2005, the global adult human biomass was about 287 million tons, 15 million of which can be traced back to overweight people, and 3.5 million of which are the result of obesity.
Not all of this extra biomass is distributed equally. North America has just 6% of the planet’s population, but 34% of its biomass comes from obesity. For some perspective, Asia has 61% of the world’s population and just 13% of biomass from obesity.
The Guardian has created a handy visualization, available here, to see the outsized proportion of human biomass in the U.S. (the country is the biggest circle). That little dot to the upper left of the U.S. is China.
Here’s the scariest part: If every country had the same body mass index distribution as the U.S., it would equal the equivalent in mass of an extra 935 million people of average BMI, with energy requirements for an additional 473 million people.
The rest of the world isn’t about to get as fat as the U.S. in the immediate future. But the trends point towards a fatter global future. Reports show that obesity is in the rise worldwide, with weight gain and malnutrition coexisting in many lower-income nations. With a growing world population already threatening the precarious ecological sustainability of the planet, we can’t exactly afford to have the current population gobbling up more than its fair share of resources. As the researchers conclude, "Tackling population fatness may be critical to world food security and ecological sustainability."