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. By comparison, about a third of Americans are obese, and eight percent are diabetic. Qatar also has very high rates of birth defects and genetic disorders -- problems that, along with the prevalence of obesity (PDF) and diabetes, have worsened in recent decades, according to local and international health experts.

So what's going wrong in little Qatar?

To misappropriate a well-worn phrase: It's the economy, stupid. In September, Qatar officially became the richest nation in the world, as measured by per capita gross domestic product. It also recently became the world's biggest exporter of natural gas, and earned the title of fastest growing economy in the world. By international development standards, all this growth has happened virtually overnight, making Qataris' lifestyles much more unhealthy, and at the same time leading many to hang on resolutely to what's left of their fleeting tribal traditions -- practices that include inter-marriage between close family members and cousins.

"They're concentrating the gene pool, and at the same time, they're facing rapid affluence," said Sharoud Al-Jundi Matthis, the program manager at the Qatar Diabetes Association, a government funded health center in Doha, the capital. As a result of these factors, Qataris are becoming obese, passing on genetic disorders at an alarming rate, and getting diabetes much more often than others around the world. They're also getting diabetes a decade younger than the average age of onset, which is pushing up rates of related illnesses and complications, like hypertension, blindness, partial paralysis, heart disease, and loss of productivity. "It's a very, very serious problem facing the future of Qatar," Matthis said.

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. Doha has mushroomed from a mere blip of beige buildings on a scorched spit of sand in the mid '90s, to a glistening glass metropolis populated by luxury hotels, fleets of shiny new Land Rovers, and fast food joints, where the young people huddle after school, sheltered from the famous Arabian heat, with temperatures hovering above 105 from late spring to late fall.