Medical researchers have linked obesity with the production fructose in the body, according to new research published in the journal Nature Communications.
Reporting from the University of Colorado School of Medicine, the researchers contend that the cause of obesity and insulin resistance could be linked to both the fructose the body makes, as well as fructose consumed in food.
The find goes against the popular belief that fructose -- simple fruit sugar -- has less of a negative health impact than glucose, which is found in all major carbohydrates and is often linked with diabetes.
The research team reports that fatty liver and insulin resistance may also result from fructose produced in the liver from non-fructose containing carbohydrates.
By conducting experiments on laboratory mice, researchers found that the mice can convert glucose to fructose in the liver, and that this conversion was linked to the development of obesity and insulin resistance in mice fed glucose.
"Our studies provide an understanding for why high glycemic foods may increase the risk for obesity and insulin resistance. While some of the weight gain is driven by the caloric content and the effects of stimulating insulin, the ability of high glycemic foods to cause insulin resistance and fatty liver is due in part to the conversion of glucose to fructose inside the body," said senior study author Richard Johnson, a professor of medicine and chief of the division of renal diseases and hypertension at the UC School of Medicine.
"Ironically, our study shows that much of the risk from ingesting high glycemic foods is actually due to the generation of fructose, which is a low glycemic sugar. These studies challenge the dogma that fructose is safe and that it is simply the high glycemic carbohydrates that need to be restricted," he said.