Adipose tissue is commonly known as body fat. It is found all over the body. It can be found under the skin (subcutaneous fat), packed around internal organs (visceral fat), between muscles, within bone marrow and in breast tissue. Men tend to store more visceral fat (fat around their internal organs), leading to obesity around the middle of their abdomen. However, women tend to store more subcutaneous fat within the buttocks and thighs. These differences are due to the sex hormones produced by males and females. Adipose tissue is now known to be a very important and active endocrine organ. It is well established that adipocytes (or fat cells) play a vital role in the storage and release of energy throughout the human body. More recently, the endocrine function of adipose tissue has been discovered. In addition to adipocytes, adipose tissue contains numerous other cells that are able to produce certain hormones in response to signals from the rest of the organs throughout the body. Through the actions of these hormones, adipose tissue plays an important role in the regulation of glucose, cholesterol and the metabolism of sex hormones.