Just feel cold to stay slim

A new study has revealed that exposure to cold temperatures increases levels of a newly discovered protein that is critical for the formation of brown fat, the type of fat in our bodies that generates heat.

Researchers at the University of California, Berkeley, found that with extended exposure to chilly air, the protein, called transcription factor Zfp516, also helps the more abundant white fat in our bodies - the kind that stores excess energy - become more similar to brown fat in its ability to burn energy.

The researchers found that mice with boosted levels of the Zfp516 protein gained 30 percent less weight than control mice when both groups were fed a high-fat diet.

Hei Sook Sul, UC Berkeley professor of nutritional science and toxicology, said that knowing which proteins regulate brown fat is significant because brown fat is not only important for thermogenesis, but there is evidence that brown fat may also affect metabolism and insulin resistance.

He said that if one can somehow increase levels of this protein through drugs, they could have more brown fat, and could possibly lose more weight even if eating the same amount of food.

Unlike white fat, which stores excess energy, brown fat burns energy to keep us warm. Brown fat gets its hue from relatively high levels of mitochondria, the cell's power station. In humans, brown fat was thought to be present only in infants, but stores of it were recently discovered in adults around such vital areas as the heart, brain, neck and spinal cord.

The study was published online in the journal Molecular Cell.