Last month, Gary Taubes wrote an article in NYT Magazine in support of a hypothesis (Robert Lustig’s; watch his 2009 UCSF lecture here) that sugar, fructose in particular, was not merely bad, but downright dangerous, and might be the cause of everything from diabetes to obesity. You can read his article for the hows and whys, and Lustig’s lecture is a must-see just for the section in which he compares the metabolization of a simple carbohydrate, ethanol and sugar. When I looked him (Taubes) up, I found that he wrote an article in the same magazine about nine years back claiming that it was the carbohydrate in the meal, and not the calories, that mattered when it came to obesity and diabetes. He went on to write a book, “Good Calories, Bad Calories,” on the subject, and also gave a lecture at UC Berkeley in late 2007 (it is a real media stream. use vlc player).
I’ve not read the book yet (it is in the mail), but both the logic, and the empirical evidence Taubes provides, appeals to me. What’s interesting is that while both articles and both lectures are years apart, both Taubes and Lustig are on the same path. Both manage to turn the arrow of causality 180 degrees by saying that the conventional wisdom of weight gain = energy intake (“gluttony”) – energy outgo (“sloth”) ought to be looked at from the other angle. Something sets off the weight gain. And the result is that person either eats more, or burns less. Taubes, in fact, is perturbed when he sees scientists whose research shows that carbohydrates drive insulin which causes fat accumulation refusing to see what is in front of their eyes. One says people are obese because they are sedentary, while the other says there are so because they eat too much. They continue to blame behavior when the science shows something else is going on.
This is from a review of the book:
“Obesity is not caused by eating too much,” Taubes writes, and “exercise is not a means of prevention.” Instead, “the fewer carbohydrates we consume, the leaner we will be.” The alleged preponderance of research that has supported low-fat diets is, in fact, “inadequate.” The field of public health “purports to be a science,” he says, and yet it “functions like a religion.”
Its prophets surely meant well. Taubes describes the story of how one charismatic researcher, Ancel Keys, so firmly believed that dietary fat was responsible for heart disease that he selectively published research confirming it. Keys won enough converts to his cause that other hypotheses seemed unlikely. Pretty soon, only research that promoted the dietary-fat hypothesis received funding and popular press attention. Once the hypothesis was “confirmed,” it started to sound like common sense.
All future studies were interpreted in light of the Keys theory. For instance, numerous studies showed that “primitive” people in Africa and the Pacific islands had low incidences of heart disease, cancer, and diabetes until they encountered the supposedly high-fat Western diet.
Of course, such research ignores the fact that those “primitive” tribal diets often featured little else but saturated fats. What they really lacked were refined carbohydrates and sugars. But since it seemed implausible to scientists that anything but dietary fats could cause the fat around our middles, and that anything but cholesterol could cause blockages in our arteries, public-health authorities rejected the carbohydrate thesis. Proponents of low-carb diets, such as the late Dr. Robert Atkins, were dismissed as quacks.
The reviewer claims that Taubes fashions himself as a lone dissident when, in fact, many people accept the hypothesis. Unless major associations of medical practitioners come out in the open and say they were wrong and that carbohydrates are a problem, she is highly overestimating the consensus.
PS: I collected a few links from this article, and the comments that follow. There are things here which I haven’t linked to, such as hatchet jobs, articles, book reviews, Taubes’ responses to them, etc.