An interesting paper by the economists Shin-Yi Chou, Michael Grossman, and Henry Saffer sorts through many factors (including per capita number of restaurants, portion sizes and prices, etc.) and concludes—not surprisingly—that the spike in obesity mostly has to do with the widespread availability of very cheap, very tasty food. They also find that a widespread decline in cigarette smoking has helped drive the obesity rate. This seems sensible, as nicotine is both a stimulant (which helps burn calories) and an appetite suppressant.
