Brown fat is an entirely different animal than the white fat that we pack onto our hips to store excess calories. Instead of storing energy, brown fat actually burns glucose to produce heat (thermogenesis). It’s brown because it contains special mitochondria that produce heat from the glucose when activated by cold. Adults don’t have much of it, unfortunately, just a few grams if we’re lucky. If we had about 50 grams and were cold enough to activate it, it would actually burn about 500 calories a day.
Now scientists from the Joslin Diabetes Center have discovered that a certain type of cell within fat tissue has the potential to become either white fat or brown fat. But these cells need a little boost to become brown fat, and that boost comes from the protein BMP-7. When the undecided cells are exposed to BMP-7, they are much more likely to become brown fat.
The researchers, whose work was published in the Proceedings of the National Academy of Sciences, believe that their discovery might lead to a new weight loss therapy that could help prevent type 2 diabetes. Wouldn’t it be nice if we could just bathe our extra fat in BMP-7 and build up an onboard calorie burner that kept us warm to boot? Meanwhile, alas, white fat reigns, and exercise, diet, and a parka remain our best options.