Fructose is a simple sugar found in many foods, such as berries, melons, tree fruits, grains, and many vegetables. When fructose is eaten in its natural form from fruits and vegetables, it is accompanied by fiber and other nutrients. However, when concentrated fructose is added to soft drinks and processed foods, it is not accompanied by these healthy components and it acts as a stimulant for the appetite. This appetite stimulation can lead to increased caloric intake and subsequent weight gain. In the July 9, 2008 issues of the Medscape Journal of Medicine, investigators from Emory University and their colleagues reported that fructose now accounts for more than 10% of energy intake in the typical American diet.

Using information from the National Health and Examination Survey (NHANES III), the investigators analyzed the fructose consumption of 21,483 U.S. adults and children. They found that the average consumption of fructose was approximately 54.7 grams per day, or 10.2% of total energy intake. Sugar-sweetened drinks were the largest source of fructose, accounting for 30% of the fructose consumed.

Compared to other types of sugars, fructose worsens cholesterol and triglyceride levels, potentially contributing to the risk for heart disease. And, the addition of sugar of high-fructose corn syrup (both of which contain approximately 50% fructose) to processed foods and drinks likely contributes to increased calorie intake and obesity. Short-term clinical trials have shown that higher fructose consumption may increase insulin resistance and fat levels in the blood. Further research on the long-term effects of fructose is needed, but it seems that, no matter what, we are eating too much sugar.