Fat

Fat is a non-water soluble, greasy, soft-solid material found in animal tissues and many plants, composed of a mixture of glycerides; together with oils these make up that class of food stuffs known as simple lipids. Fats provide the most concentrated source of dietary energy, furnishing more than twice the number of calories per gram than protein or carbohydrates.

Fat deposits surround and protect organs such as the kidneys, heart and liver. Fats are the primary substance of adipose tissue. A layer of fat beneath the skin, known as subcutaneous fat, insulates the body from environmental temperature changes thereby preserving body heat.

Fats carry vitamin A, vitamin D, Vitamin E and Vitamin K, the fat-soluble vitamins.

The most abundant form of lipids, and those which are the body's concentrated energy source, are known as triglyderides and are composed of three molecules of fatty acid chemically bonded to one of glycerol. This chemical process is known as esterification.


References
Antony, C.P. & G.A. Thibodeaw. 1979. Textbook of Anatomy and Physiology. The C.V. Mosby Company, St. Louis. 731.

Guthrie, Helen A. Introductory Nutrition. 5th edition. St. Louis: C.V. Mosby Co., 1971.

Kirschmann, John D. Nutrition Almanac: Nutrition Search Inc. New York: McGraw-Hill, 1984.