Adipose tissue is one of the main types of connective tissue. In biology, adipose tissue /ˈaedɨˌpoʊs/ ˈædɨˌpoʊs or body fat or just fat is loose connective tissue composed mostly of. adipocytesat in the lower body, as in thighs and buttocks, is subcutaneous and is not consistently spaced tissue, whereas fat in the abdomen is mostly visceral and semi-fluid. Visceral fat is composed of several adipose depots, including mesenteric, epididymal white adipose tissue (EWAT), and perirenal depots.