Scientists say they have found what they believe is the gene strongly linked to obesity.

The study published in the scientific journal Nature shows that mice bred without the IRX-3 gene were 30 percent lighter than mice bred with the gene.

Both groups of mice ate the same diet and exercised the same. But the thin mice were found to be resistant to diabetes and burned energy more efficiently.

The researchers say there is a similar gene in humans, and that their findings could lead to a drug to treat obesity and diabetes -- a disease sometimes linked to being overweight.

Scientists from the University of Chicago led the study.

Obesity is a major global health problem, killing millions of people every year. Poor diet and little exercise are among the major causes of obesity, while the problem may be genetic in others.

Some information for this report comes from AFP.