Brown fat, also called brown adipose tissue, is a special type of body fat that is turned on, or activated, when you get cold. Brown fat produces heat to help maintain your body temperature in cold conditions. Brown fat contains many more mitochondria than white fat. These mitochondria are the "engines" in brown fat that burn calories to produce heat.

Brown fat has generated interest among doctors and researchers for some time because it appears to be able to use regular body fat as fuel. And equally promising, it looks as if exercise may stimulate hormones that activate brown fat.

Researchers are looking at whether brown fat's calorie-burning properties can be harnessed for weight loss. It's too soon to know whether these efforts will pay off. In the meantime, be sure to include physical activity in your weight management plans.

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Sept. 23, 2015 See more Expert Answers