Epidemiologists have been busy with obesity, particularly in the most overweight country, the US. By 2040, predicts one study, 100% of Americans will be either overweight or obese, if current trends hold.
If you want to watch the trends in US obesity, and to understand how race, income and gender matters, you’re in luck. I’ve stumbled upon a fine site, with great data, courtesy of, er, The Endocrine Society and the Hormone Foundation. Obesity in America has the details.