Suprise! It's not the United States - although one third of Americans are overweight, we look downright svelte compared to Qatar:
Qatar is a tiny country with a big problem.
This Connecticut-sized nation, sticking out like a loose tooth in the Persian Gulf, is one of the most obese nations in the world, with residents fatter, on average, than even those of the United States, which often takes the cake in such competitions.
According to recent studies, roughly half of adults and a third of children in Qatar are obese, and almost 17 percent of the native population suffers from diabetes. [...] So what's going wrong in little Qatar? [...]
Over the course of two generations, most native Qataris, who number only 250,000 in a nation of 1.7 million, and enjoy the benefits of a robust welfare state, went from living modest, tribal lifestyles in the Arabian desert, to living in air-conditioned villas with maids, nannies, gardeners, and cooks.
Haley Sweetland Edwards wrote the report for The Atlantic: Link
The pacific island nation of Nauru is officially recognised as the fattest country on earth. There 4 in every 5 people are obese.