How much do we love sugar? The amount may surprise you – the average American eat about 3,550 pounds of sugar and 313 gallons of high fructose corn syrup in a lifetime. And according to Dr. Robert Lustig, UCSF expert on pediatric hormone disorders and childhood obesity, it’s killing us…

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.


Illustration: Kenji Aoki / The New York Times; Prop Stylist: Nell Tivnan. Source: UI.S.D.A. 2009 Estimates

See also Lustig’s fascinating lecture, Sugar: The Bitter Truth, about how bad the sweet stuff is for us.