Brown adipose tissue

Brown adipose tissue (BAT) or brown fat is one of two types of fat or adipose tissue (the other being white adipose tissue, or white fat) found in mammals.

Importantly, classification of brown fat in humans refers to at least two distinct cell populations with similar functions. The first shares a common embryological origin with muscle cells, found in larger "classic" deposits. The second develops from adrenergically induced adipocytes, found interspersed in white adipose tissue.