White adipose tissue (WAT) is organized into distinct depots, classified by location as subcutaneous or intra-abdominal. The major subcutaneous WAT includes the abdominal, gluteal, and femoral depots. Other white subcutaneous depots include the cranial and facial adipose tissue. Intra-abdominal adipose tissue is located within the peritoneum and includes the omental, retroperitoneal, and visceral (mesenteric) fat. White adipocytes also accumulate in other locations, including behind the eye (retro-orbital), around joints (periarticular), in bone marrow, surrounding the heart (pericardial), and within the skeletal muscle (intramuscular). Brown adipose tissue (BAT) in adults exists as a heterogeneous tissue, containing brown and beige adipocytes interspersed with white adipocytes. BAT depots are located in the cervical, supraclavicular, and paravertebral regions in adults.