A substance in grapefruit could prove to be the key to fighting both obesity and diabetes, according to a new Canadian study. The substance, a flavonoid called “naringenin,” is a naturally occurring compound found in all citrus fruit, but especially in grapefruit, giving it its characteristic bitter taste. Naringenin, in concentrations far above levels found naturally, makes the liver burn fat instead of storing it, according to a study by Roberts Research Institute at the University of Western Ontario.

The study used two groups of mice which were fed a typical Western high-fat diet, a diet known to induce symptoms of metabolic syndrome. One group’s diet, however, was treated with naringenin. The researchers found that the naringenin corrected elevations in tryclycerides and cholesterol, prevented the onset of insulin resistance, and otherwise normalized the metabolism of insulin. Also, the naringenin completely reprogrammed the livers of the mice so that excess fat was burned rather than stored.

Study leader Murray Huff said that the “marked obesity that develops in these mice was completely prevented by naringenin. What was unique about the study was that the effects were independent of caloric intake, meaning the mice ate exactly the same amount of food and the same amount of fat. There was no suppression of appetite or decreased food intake, which are often the basis of strategies to reduce weight gain and its metabolic consequences.”

The famous grapefruit diet was apparently headed in the right direction, but the levels of naringenin found in grapefruit were not high enough to produce the results obtained in the study. People wanting to try naringenin for obesity and diabetes benefits will have to wait until a concentrated supplement is developed. The study team is in fact trying to develop a naringenin treatment for humans.