'Brown' fat could assist in weight loss in adult humans

NPR - Brown Far: Don't Try to Burn It
and
ScienceNews - The Other, Friendly Fat

'Brown' fats are so-called because of the large concentration of mitochondria (calorie burning cellular organelles) found in them, and their connection to red-blood capillaries. They are now known to remain present in adult humans (while it was previously thought they were in human babies but not adults). Brown fats are found in the neck, shoulders and back, and decline in adults as they grow older (rapid decline past age 50) and if they become overweight. The interesting thing about these fats is that they burn calories, especially acting as a sort-of heat source for the body once the air temperature drops to about 61f. Brown fats may decline in adults as 'white' fat increases, providing a layer of insulation and therefore requiring less heat production.