Researchers at the London School of Hygiene and Tropical Medicine have published a study in this month's BMC Public Health claiming the collective population of the world is 17 million tons overweight.

Prof. Ian Roberts, one of the study's authors, says the goal was to move away from the focus on obesity in individuals. "One of the problems with definitions of obesity is that it fosters a 'them and us' ideal," he told BBC News. "Actually, we're all getting fatter."

That being said, some are still significantly fatter than others.

Roberts and his team found that, despite accounting for only 6% of the global population, North America was single-handedly responsible for a third of the world's obesity. Compare that with Asia: 61% of the global population, but only 13% of its obesity.

2005 World Health Organization figures used by the researchers make the North American contribution even clearer: While the global body weight average stood at 137lbs, the average North American clocked in at 178lbs — over 50lbs heavier than the average Asian.

"If every country in the world had the same level of fatness that we see in the USA," Prof. Roberts said, "in weight terms that would be like an extra billion people of world average body mass."

Much like his counterparts at the University of North Carolina, Prof. Roberts too blamed a lack of physical activity on the sharp increase in weight gain.

"One of the most important determinants of average body mass index is motor vehicle gas consumption per capita," he said. "So, it is no surprise to see many of the Arab countries in the list - people eat but they move very little because they drive everywhere."

While the US leads the world in fatness, Roberts said rapidly developing nations are catching up: "China's getting fat really quickly; India's getting fat really quickly."

[photo via Shutterstock, infographic via The Daily]