Scientists from McGill University in Montreal, Canada, have isolated the gene in mice that turns bad (white) fat into good (brown) fat.

In a study published in Nature Medicine 2001 (pp. 1102-1103, 1128-1132), Dr Nahum Sonenberg and his colleagues explained how they were able to create leaner mice, which could eat as much as fatter mice, by inactivating a metabolism-related gene that encodes a protein called 4E-BP1. With this gene gone, the animals’ bodies converted some of their fat stores into a more weight-friendly fat that promotes calorie burning. Overall, the study found that mice without the 4E-BP1 gene weighed about 10% less than normal mice, despite eating the same amount of food.

Sonenberg explained to Reuters Health that the experiments were carried out after the scientists compared a group of mice that lacked the gene for 4E-BP1 with normal animals. Before the tests, no one knew that the 4E-BP1 gene was involved in metabolism.

Sonenberg added that the findings could help in the fight against obesity in humans, by offering a chance to convert the bad fat stores into more efficient fat. He stressed however that a magic pill is unlikely to become available in the near future.