Fructose is having a public relations crisis. Its reputation started to take a nosedive several years ago when some nutrition experts suggested that Americans eat far too much of it and that it is a major cause of the so-called obesity epidemic. Things got worse when studies provided a measure of support for this opinion.
While fructose is a natural sugar found in many fruits, most of the fructose in the American diet takes the form of high-fructose corn syrup, a processed sugar added to soft drinks, candy, and other foods. The body metabolizes fructose in a somewhat different way than it does other sugars—a way that possibly promotes metabolic syndrome. For example, a study published recently in Nutrition & Metabolism reported that 10 weeks of drinking fructose-sweetened beverages significantly increased uric acid levels and other markers of metabolic syndrome in overweight subjects, whereas glucose-sweetened beverages did not.
However, other studies supply evidence that pinning the country’s weight problem on fructose may be unfair. Researchers at the University of Rhode Island and the Rippe Lifestyle Institute recently investigated the effects of a 12-week hypocaloric diet (where subjects ate 309 fewer calories per day than their bodies used) on weight loss. Participants were separated into four groups, each of which was given a different amount of sucrose or high-fructose corn syrup.
The researchers were interested in seeing whether including large amounts of HFCS in the diet made it harder for people to lose weight on a hypocaloric diet. Turns out it didn’t. Subjects in the high HFCS group lost just as much body fat as members of the other three groups. The authors of the study concluded, “Similar decreases in weight and indices of adiposity are observed when overweight or obese individuals are fed hypocaloric diets containing levels of sucrose or high fructose corn syrup typically consumed by adults in the United States.”
This doesn’t mean your diet should include as much HFCS as the average American’s. Added sugars account for 14 percent of total calories in the typical American diet. That’s too much. On the other hand, don’t make the mistake of lumping all sources of sugar together. Some health-conscious eaters have taken their fear of fructose so far that they avoid fruit. That’s insane. We’re talking about fruit, people! The fructose in fruit will not harm you. In fact, a study from the Harvard School of Public Health found that eating a lot of fruit prevents long-term weight gain even more effectively than eating a lot of vegetables.
Some athletes avoid sports drinks and energy gels that contain fructose. This is not necessary, either. While research has shown that sports drinks and energy gels that contain more than one sugar are more effective than those that contain a single type of sugar (whether it’s fructose or something else), there is nothing bad about the presence of fructose in such products provided they are used as intended: before, during, and after exercise.