Exercise, not food, is key to obesity epidemic

With statistics pointing to about a third of U.S. adults obese, studies are attempting to pinpoint the sources of the obesity epidemic. A recent study from Stanford University School of Medicine over two decades points to lack of exercise and not overeating as the main cause.

Background:

What's more to blame for obesity: Lack of exercise or eating too much? [CBS News]

Obesity: We're not overeating, we're under-exercising, study suggests [LA Times]