Fat switch may offer new obesity approach: study

WASHINGTON (Reuters) - Helping switch on an energy-burning type of fat called brown fat may offer a way to prevent obesity, researchers reported on Tuesday.

They found a gene called PRDM16 in brown fat but not in white fat -- the type of fat found all over the bodies of most adult humans.

It may be possible to use this gene, or the protein whose production it controls, to help stop people from making too much white fat, the team at Harvard Medical School and the French research institute INSERM in Toulouse said.

"Brown fat is present in mice and in human infants, where it keeps them warm by dissipating food energy as heat, instead of storing it as white fat," said Dr. Bruce Spiegelman of Harvard's Dana Farber Cancer Center.

In humans, it all but disappears by adulthood, the researchers wrote in their report, published in the journal Cell Metabolism.

The question is whether humans can be taken back to an infantile state in which brown fat counteracts the buildup of white fat.

Spiegelman's team genetically engineered fat precursor cells with PRDM16 and injected them under the skin of mice.

The PRDM16 gene helped turn the cells into brown fat cells. It may be possible to do the same in people, Spiegelman said.

"You might not have to implant a large amount of engineered precursors in people who are at risk for being obese," Spiegelman said in a statement. One percent might do it, he said.