This institutional absolution of sugar might have been relatively innocuous had it not been coincident with the introduction of a type of sugar refined from corn, rather than sugarcane or beets, known as high-fructose corn syrup, or HFCS, and specifically with what is technically known as HFCS-55, a sweetener that is 55 percent fructose and 45 percent glucose and was created to be indistinguishable from sucrose by taste when used in soft drinks. HFCS-55 entered the market in 1978. By 1985, half of the sugars consumed each year in the U.S. came from corn sweeteners, and two-thirds of that was high-fructose corn syrup. More important, the average consumption of sugars in total had started climbing steadily upward.

This rise in sugar consumption is one of the more perplexing dietary trends in the last century. Though Americans’ taste in starch apparently ebbed and flowed through the twentieth century, the average yearly consumption of caloric sweeteners—a category that includes table sugar, corn sweeteners, honey, and edible syrups—remained relatively constant from the 1920s, at 110–120 pounds per capita. It began to inch upward in the early 1960s, coincident with the first introduction of fructose-enhanced corn syrups. With the introduction of HFCS-55, it increased significantly. According to USDA statistics, between 1975 and 1979 Americans consumed an annual average of 124 pounds of sugars per person. By 2000, that number had jumped to almost 150 pounds. Corn sweeteners, and particularly high-fructose corn syrup, constituted virtually every ounce of the increase. And this increase came on the heels of a period in the mid-1970s when sugar consumption per capita was decreasing, as sugar was being portrayed in the popular press as a fattening and addictive dietary nuisance.

The simplest explanation for the increase in caloric-sweetener consumption is that consumers simply failed to equate high-fructose corn syrup with the sugar that we’d been eating almost exclusively until then. Although HFCS-55 is effectively identical to sucrose upon digestion, the industry treated it, and the public perceived it, as a healthy additive, whereas sucrose carried the taint of decades of controversy. Because fructose is the predominant sugar in fruit—an apple, for instance, is roughly 6 percent fructose, 4 percent sucrose, and 1 percent glucose by weight—it is often referred to as “fruit sugar” and appears somehow healthier simply by virtue of that association. And, of course, fructose was perceived as healthy because it does not elevate blood sugar and has a low glycemic index.

As a consequence, high-fructose corn syrup could be used as the primary sweetener, and often the primary source of calories, in products that had the outward appearance of being healthy or natural, or were advertised as such, without revealing the products to be little more than sugar, water, and chemical flavoring. This included sports drinks such as Gatorade, the fruit juices and teas such as Snapple that appeared nationwide beginning in the late 1980s, and low-fat yogurts, which also exploded in popularity with the condemnation of fat in the diet.