If you think that Mayor Bloomberg's anti-sugar and high-fructose corn syrup (HFCS) campaign has been more than a little gross, just wait until Hizzoner picks up the Times Magazine this weekend. In it writer Gary Taubes offers up more than 6,000 words on the how-can-you-not-click-it topic of "Is Sugar Toxic?" And he makes a convincing argument that we would like to forget now.

Taubes builds the story around a 90-minute lecture on YouTube given by Robert H. Lustig of UCSF, in which the professor persuasively argues that sugar is a "toxin," or "poison." And when he says sugar he means not just the sucrose you put in your coffee but also the much-maligned-of-late HFCS. How toxic? While it isn't an "'acute toxin' of the kind the F.D.A. typically regulates" there are some good arguments in there that sugar is at the least not helping anyone and at the worst a major culprit in the rise in cases of obesity and diabetes in the Western world.

Oh, and he also gets the president of Memorial Sloan-Kettering Cancer Center—who knows a thing or two about cancer—to admit that “I have eliminated refined sugar from my diet and eat as little as I possibly can, because I believe ultimately it’s something I can do to decrease my risk of cancer.”

But isn't sugar just empty calories? How is something so sweet responsible for so many ills? Here's how (some of) the argument goes:

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 H.F.C.S. 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.

In animals, or at least in laboratory rats and mice, it’s clear that if the fructose hits the liver in sufficient quantity and with sufficient speed, the liver will convert much of it to fat. This apparently induces a condition known as insulin resistance, which is now considered the fundamental problem in obesity, and the underlying defect in heart disease and in the type of diabetes, type 2, that is common to obese and overweight individuals. It might also be the underlying defect in many cancers.

So. Hm. Maybe we should ease back on the sugar?

And here's Lustig's video: