Just learned about Brown Fat this morning … a friend described it perfectly to me:
Brown fat burns calories. White fat just sits there looking like hail damage.
That’s not really fair to white fat. For most of human history, having the ability to store fuel reserves to deal with food shortages was extremely beneficial.
Humans have very little brown fat, although there are a number of studies that show that it exists.
I think if you are looking for a tissue that burns a bunch of energy, I’d focus on developing lean muscle. We are 40% muscle, and the metabolic contributions of muscle in humans are considerably greater than the 100 g or so of brown fat.