So-called beige fat -- pea-sized deposits found beneath the skin near the collarbone and along the spine -- actually burns off calories rather than storing them, US researchers have discovered.

This could lead to new therapies for obesity and diabetes, lead researcher Bruce Spiegelman of the Dana-Farber Cancer Institute in Boston said in a release Thursday.

The study found beige fat is genetically distinct from brown fat, which also burns calories to generate heat.

Brown fat is most commonly found in small mammals and human infants, where it protects against harm from cold.

White fat stores calories and excess white fat contributes to obesity.

Brown fat in adult humans was only discovered recently. In January, Quebec researchers reported brown fat also works to burn off calories.

A study by Spiegelman's team earlier this year reported the discovery of irisin, which is produced by muscular exercise and can convert white fat to brown fat.

"Going forward, it means that what you want to study for potential therapies are the beige fat cells in these 'hot spots' we're all walking around with," Spiegelman said.

The most recent study was released online on Thursday, and will appear in the journal, Cell, on July 20.