Looking beyond obvious causes of obesity like overeating, scientists said on Wednesday they may have found a gene that also plays a role, one that helped our ancestors survive famines.

Targeting this thrifty gene and others with diagnostic tests and drugs offers another way to fight the global epidemic of obesity, the researchers said.

Mice bred to lack this gene, known as CRTC3, can eat a high-fat diet without gaining weight, while normal mice on the same diet grow plump, the researchers found.

And Mexican Americans who have an especially potent version of this gene are more likely to be obese than others, Dr. Marc Montminy of the Salk Institute for Biological Studies in California and colleagues reported in the journal Nature.

The gene did not appear to have the same effect in whites, which supports what scientists know — that obesity is very complex. But CRTC3 is clearly important.

tehran times : Too fat? Study fingers one “thrifty gene” suspect