Post Hoc, Ergo Proctor Hoc?

Just because two events follow each other does not mean that the second event was caused by the first. This is the fallacy that can occur when trying to deduce the cause of historical events by correlating that event with other historical events. I find it interesting that a newspaper would print two articles on the same day that both attempt to imply that the nations obesity resulted from a specific change: in one case the use of high fructose corn syrup and in the other the reduction in the use of fat.

First for the sweet:

An overweight America may be fixated on fat and obsessed with carbs, but nutritionists say the real problem is much sweeter — we’re awash in sugar.

Not just any sugar, but high fructose corn syrup.

The country eats more sweetener made from corn than from sugarcane or beets, gulping it down in drinks as well as in frozen food and baked goods. Even ketchup is laced with it.

Almost all nutritionists finger high fructose corn syrup consumption as a major culprit in the nation’s obesity crisis. The inexpensive sweetener flooded the American food supply in the early 1980s, just about the time the nation’s obesity rate started its unprecedented climb. [SFGate]

Next the fat:

Many dietitians now admit their one-size-fits-all approach to fat consumption is outdated, even going so far as to endorse such former pariahs as highly saturated coconut and other tropical oils.

The shift is driven as much by changing social attitudes as by stark epidemiological evidence: Despite a 30-year low-fat frenzy, Americans are fatter than ever, more than 65 percent classified as overweight or obese.

The nation’s obesity rate began to skyrocket in the mid-’80s — about the same time national low-fat public health campaigns were in full swing. In one year alone — 1998-99 — Centers for Disease Control and Prevention figures show that the nation’s obesity rate rose an astonishing 6 percent. [SFGate]

While I am not saying that I know, specifically, why Americans are fat. I am not saying even that there is a single simple explanation. I believe that there may be some truth to both of these arguments. In fact, both arguments sound highly plausible, perhaps even more so when taken together. What I am trying to say is perhaps explained by this quotation:

We should be careful to get out of an experience only the wisdom that is in it — and stop there; lest we be like the cat that sits down on a hot stove lid. She will never sit on a hot stove lid again — and that is well; but also she will never sit down on a cold one anymore. — Mark Twain

My recommendation is simple: Do More; Eat Less. Eat a balanced, varied diet — nothing to excess — and match your diet to your activity level — or your activity level to your diet — your choice.