Washington: A lower body fat level may not always lower your risk for heart disease and diabetes, researchers say.
Douglas P. Kiel and David Karasik, researchers at Harvard Medical School, identified a gene linked with less body fat, but also with a higher risk of type 2 diabetes and heart disease, examples of so-called "metabolic diseases".
"We`ve uncovered a truly fascinating genetic story and, when we found the effect of this gene, we were very intrigued by the unexpected finding," says Kiel, senior scientist and professor of medicine at Harvard.
"People, particularly men, with a specific form of the gene are both more likely to have lower percent body fat, but also to develop heart disease and type 2 diabetes," the journal Nature Genetics quoted Kiel as saying.
"In simple terms, it is not only overweight individuals who can be predisposed for these metabolic diseases.
"Some collections of fat, such as the kind located just under the skin, may actually be less harmful than the type located in the abdominal cavity, which may increase the risk of developing metabolic disease," Kiel said, according to a Harvard statement.
Investigators examined the genomes of more than 75,000 people to look for the genes that determine body fat percentage. They found strong evidence for a gene, called IRS1, to be linked with having less body fat.
On further study, they found that this gene also leads to having unhealthy levels of cholesterol and blood glucose.
The researchers speculate that people with this gene variant are less able to store fat safely under the skin and may, therefore, store fat elsewhere in the body, where it may interfere with normal organ function.
All observations were more pronounced in men than in women and, indeed, many apparently lean men still carry too much abdominal fat.