Are We Sugar Crazy?

A critique of the sugar-is-poison debate.


The acrimony directed at sugar, in all its forms, has taken a particularly bitter turn of late, with the suggestion that sugar is a poison and should be regulated as such through some combination of taxes, product bans, and dose restrictions. Is this rational, or maybe just a bit crazy? Let's chew on it.

Excess dietary sugar is irrefutably harmful. The calories provided—whether from sucrose, high-fructose corn syrup, or any other variant—are empty, carrying no nutritional benefit to offset the cost, and they contribute to weight gain and obesity. The glycemic effect of sugar—its tendency to raise blood sugar, and in some cases insulin—can further contribute to extra pounds and obesity, as well as hormonal imbalances, insulin resistance, and ultimately, diabetes. Such, by and large, is the epidemiologic indictment of sugar.

There is, as well, an indictment based on dietary guidance: Americans eat considerably more, on average, than the 10 percent of daily calories that authorities such as the World Health Organization, the American Heart Association, the Institute of Medicine, and the Dietary Guidelines advise should come maximally from added sugars, and the 25 percent that should come from total sugars. And there is even a biochemical indictment, based on the fact that high levels of sugar, and perhaps fructose in particular, can be linked to vital organ injury. Most notably it has been tied to liver damage resembling the effects of alcohol, as described most vividly and adamantly by Robert Lustig of the University of California–San Francisco. All of which seems to suggest we should just go ahead and convict sugar as a toxin, and regulate it. But I don't think it is, and I don't think we should.

Sugar is a native part of the Homo sapiens diet. Babies get it first from breast milk, and virtually all humans also consume fruits as part of their native diet. Glucose floats in the blood and must remain above a particular concentration at all times or a person will succumb to nausea, fainting, seizure, and, without prompt remediation, death. If adequate sugar is not consumed, the body will make "sugar" in the liver from any nutrient source available to maintain that crucial level in the bloodstream.

So sugar cannot be avoided entirely. And then there is the question: What will people wind up eating instead? Soda isn't the only product that can be artificially sweetened. Doughnuts, Danish, and muffins can, too. But the starches these foods are made of often have a higher glycemic index than sugar itself. Though researchers have demonstrated that improving the overall quality of the diet is powerfully good medicine for both health and weight, to date, the "one nutrient at a time," or ONAAT, fallacy has led to nothing but compounded troubles. We added oat bran, cut fat, cut carbs, yet still got fatter and sicker each time. If sugar is regulated, it could open the floodgates to artificially sweetened everything, leading people to eat even more products that are unsound in other ways. We could well repeat the follies of nutritional history.

There are better ways to go, like measuring the overall nutritional quality of foods with a validated scoring index, such as NuVal (, which I helped develop and is now being licensed to retail grocery chains around the country, like Hy-Vee, Meijer, and Price Chopper. NuVal places a suitable emphasis on sugar, along with starch, glycemic load, artificial sweeteners, and every other nutrient property that truly matters. In addition, financial incentives (or disincentives) could be tied to such a metric. Health insurers for years have been offering better rates to companies offering wellness programs and to employees who use them. Incentives that reduce the cost of the most nutritious foods could be provided by those currently paying the much higher costs of disease care: insurance companies, employers, and the government. The public, too, can be better educated about the abundance of added "stealth" sugar in seemingly unsweet foods.

Do we eat too much sugar? Yes. Can policy help fix that? Again, yes. But to suggest that sugar is the only thing wrong with the modern diet and a poison is a distortion that risks both distraction and backlash. To take a slight liberty with the Yiddish for "crazy," it's a bit misugarna!

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David L. Katz, MD, MPH, FACPM, FACP, is a specialist in internal medicine and preventive medicine, with particular expertise in nutrition, weight management, and chronic-disease prevention. He is the founding director of Yale University's Prevention Research Center, and principal inventor of the NuVal nutrition guidance system. Katz was named editor-in-chief of Childhood Obesity in 2011, and is president-elect of the American College of Lifestyle Medicine.

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