Brown fat and white fat, illustration. Male and female figures, and a child seen from the front and rear, showing typical location of the two types of fat: brown and white. Brown fat (orange), also known as brown adipose tissue (BAT) is especially abundant in newborns. Its primary function is thermoregulation, producing heat by a process known as non-shivering thermogenesis. In adults brown fat is present in the upper chest and neck, especially alongside the vertebrae. White fat, also known as white adipose tissue (WAT), makes up 20 to 25 percent of healthy body weight in adults. It functions as a store of energy. It is found under the skin on the abdomen in men, on the hips in women, and around some internal organs in both sexes. |