Pretty good article but a bit oversimplified. Yes for sure the amount of food people eat is responsible for the rising obesity figures. I've said it before and I'll say it again here, it's economic in nature. The price of food has dropped drastically since the 70's, and surprise surprise waistlines have increased since then at a corresponding rate. However, that's about statistics and the behaviour of entire populations, not individuals. I think if the obesity numbers were broken down by age groups, we'd find that the 40+ age group probably represents the overweight by a disproportionate amount. The simple fact is, it's easier to stay lean for 20 and 30 year olds than 40+. In fact I think for really young people, say <20, exercise probably is 80-90% of the leanness equation, for 20-30 yrs 60-70% of the leanness equation, and for 40+ 10-20%. So the importance of exercise w.r.t. controlling weight is huge for kids, but diminishes as we get older, until diet nearly entirely trumps exercise. So, good article, but not terribly comprehensive.