This article in the New York Times really makes you rethink obesity. Researchers found that fat people who lost weight looked like skinny people, but were metabolically more like starving people. They also found that people who were adopted had fat levels closer to their biological parents than their adopted ones, disproving that environment is the main factor in obesity. The reverse was true too: they had skinny people stuff themselves to gain weight, and it took months to gain 20 lbs. And as soon as they were off the fat diet, they quickly lost weight.
Makes you think twice about muttering under your breath when you see an overweight person eating at McDonalds. They can’t really help it.