The Root of American Obesity Problem Explained by a Mathematician

Americans have been wringing their hands about the problem of obesity for decades (for some of us, while munching on snacks), but never before has the problem been attacked from the perspective of ... math!
In 2004, mathematician and physicist Carson Chow was tasked with figuring out why more and more Americans are getting fatter. When he started, Carson said that "[he] knew almost nothing of obesity. [He] didn't even know what a calorie was."
But he could clearly see a trend: Since 1975, the average weight of Americans jumped by about 20 pounds and the national obesity rate went from 20% to 30%. So what gives?
Claudie Dreifus interviewed the math whiz for The New York Times:

Did you ever solve the question posed to you when you were first hired — what caused the obesity epidemic?
We think so. And it’s something very simple, very obvious, something that few want to hear: The epidemic was caused by the overproduction of food in the United States.
Beginning in the 1970s, there was a change in national agricultural policy. Instead of the government paying farmers not to engage in full production, as was the practice, they were encouraged to grow as much food as they could. At the same time, technological changes and the “green revolution” made our farms much more productive. The price of food plummeted, while the number of calories available to the average American grew by about 1,000 a day.
Well, what do people do when there is extra food around? They eat it! This, of course, is a tremendously controversial idea. However, the model shows that increase in food more than explains the increase in weight.

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