Skip to content

Sweet Science

Gary Taubes, whose book Good Calories, Bad Calories has been very influential among the paleo community (perhaps best exemplified by former UC Irvine economist Art De Vany), has an excellent article in this week’s New York Times Magazine:

“Lustig’s argument, however, is not about the consumption of empty calories — and biochemists have made the same case previously, though not so publicly. It is that sugar has unique characteristics, specifically in the way the human body metabolizes the fructose in it, that may make it singularly harmful, at least if consumed in sufficient quantities.

The phrase Lustig uses when he describes this concept is ‘isocaloric but not isometabolic.’ This means we can eat 100 calories of glucose (from a potato or bread or other starch) or 100 calories of sugar (half glucose and half fructose), and they will be metabolized differently and have a different effect on the body. The calories are the same, but the metabolic consequences are quite different.

The fructose component of sugar and high-fructose corn syrup is metabolized primarily by the liver, while the glucose from sugar and starches is metabolized by every cell in the body. Consuming sugar (fructose and glucose) means more work for the liver than if you consumed the same number of calories of starch (glucose). And if you take that sugar in liquid form — soda or fruit juices — the fructose and glucose will hit the liver more quickly than if you consume them, say, in an apple (or several apples, to get what researchers would call the equivalent dose of sugar). The speed with which the liver has to do its work will also affect how it metabolizes the fructose and glucose.”

Definitely W1OY20 material.