ADIPOSE TISSUE is composed of specialized connective tissue cells which contain large globules of fat. The chief chemical constituents of this fat are the neutral glycerol esters of stearic, oleic and palmitic acids. The fat stored in these cells comes in part directly from the fats eaten, and in part is manufactured within the body from fats and carbohydrates in the food and sometimes from protein. The main reservoir of fat in the body is the adipose tissue beneath the skin, called the panniculus adiposus. There are also deposits of fat between the muscles, among the intestines and in their mesentery, around the heart, and elsewhere. Beside acting as a fuel reserve against times of starvation or great exertion the panniculus adiposus conserves the heat of the body. Fat also seems to be a factor in resistance to disease, since undernourished people are more prone to infections than those in a good state of nutrition.