We may worry that too many people are draining the planet's resources—but in fact, "it's not how many mouths there are to feed, it's how much flesh there is," a researcher says. His study shows that if every country in the world were as fat as the US, it would be comparable to having an extra billion people on the planet, the BBC reports. Altogether, the human population weighs some 316 million tons; researchers blame 16.5 million tons on people being overweight and 3.9 million tons on obesity.
Perhaps unsurprisingly, a chunk of that excess weight is found in North America: We account for about a third of global obesity but just 6% of population. Asia, by contrast, holds 61% of the world's population, but holds just 13% of the world's obesity-linked weight. The world's average weight is 137 pounds, but North America's average is 187 pounds, while Asia's is 127. Scientists stress that we're all in this together: Talking about obesity often "fosters a 'them and us' ideal," notes one. "Actually, we're all getting fatter." (Read more obesity stories.)