Diet and Nutrition

Overweight? Don't Blame the Fructose

Overweight? Don't Blame the Fructose

A new review suggests that natural sweeteners cannot be blamed for gaining weight. The analysis of data from the scientific literature is published in, Annals of Internal Medicine. The results of the review clearly shows that it is not any specific property of fructose, but the overall calorie intake that is the real culprit for causing an individual to gain weight. Researcher John Sievenpiper, MD, PhD, of McMaster University in Hamilton, Ontario, Canada, reports that fructose is not really the source of metabolic problems as per their study. Since the study has many drawbacks the results cannot be taken without any caution. The results are preliminary to be recommended for a healthy weight and living, adds the researchers.

The review was based on a 41 studies from the literature. The studies fall into one of the two broad categories of studies. A total of 31 studies divided the participants into two groups – one group assigned to fructose while the other a different type of carbohydrate. All the participants had the same amount of calories, despite the difference in the type of carbohydrate. This helped the researchers to isolate the data from fructose intake and its effect on the changes in body weight. They could not find any significant relationship between the intake of natural sweeteners and gain in body weight.

The remaining 10 studies in the review assessed the effect of adding more calories. One group of participants had their usual diet, while the second group added extra fructose to their normal diet. The group who had extra fructose gained weight, which was equivalent to the extra calories added by the fructose. “This result shows that energy or calorie is the dominant factor," says Sievenpiper.

This is contradictory to the general belief that intake of fructose is the leading cause of obesity epidemic, particularly when it is taken in the form of fructose corn syrup. Fructose corn syrup is normally added to non-diet soft drinks and other food products. According to Sievenpiper, fructose acts like any other energy-dense substance. “This analysis shows that people should not be worrying about one particular sugar but about the total calories consumed," remarks Laura Jeffers, MEd, RD, LD, from Cleveland Clinic.

David Heber, MD, PhD, director of the UCLA Center for Human Nutrition, disagrees with the fact and says that everybody should be focusing on amount of fructose consumed and from where it is obtained. According to him, we have a large amount of fructose from fruits and vegetables and that is not a concern.

Sievenpiper cautions that this review cannot be considered as a representative of real-world situations. Most of the study, according to the review, had issues with methods and time, with many studies that were conducted were too short. According to him, large, long-term trials would be better to assess the effect of fructose rather than calories, particularly with respect to weight gain, and these studies should be done in real-world formats.

This means that studies should focus on the different types of fructose, like real corn fructose, and those found in fruits and vegetables. It is also important to consider the means by which it is consumed, like in sweetened fruit drinks. The form in which fructose is taken is important because fluid foods add calories to the diet but does not satisfy hunger. This leads to overindulgence.