This page provides information about fats, the composition & constituents of fats, saturated and unsaturated fats, cholesterol and functions of fats.
Fats are made of carbon, hydrogen and oxygen, but they differ from carbohydrates in that the hydrogen and oxygen are not in the same proportion as in water. Fats are classified into two groups: Saturated and Unsaturated.
Saturated or animal fat contains mainly saturated fatty acid and is found in milk, cheese, butter, eggs, meat and oily fish such as herring, cod and halibut. Almost all animal sources of protein contain some amount of saturated fat.
Cholesterol is synthesized in the body and is also obtained in the diet from full fat dairy products, fatty meat and egg yolk.
Unsaturated or vegetable fat, containing mainly unsaturated fatty acids and glycerol, is found in some margarine and in most vegetable oils.
Linoleic, linolenic and arachidonic acids are poly-unsaturated fatty acids that are essential in the diet because they cannot be synthesized in the body. They are the precursors of prostoglandins, thromoboxanes and leukotrienes.
Functions of fat
Fats play the following roles in the body:
Provision of a source of chemical energy and heat
Support of certain body organs
Transport and storage of fat soluble vitamins A, D, E and K
Constituent of nerve sheaths and of sebum
Formation of cholesterol and steroid hormones
Storage of energy as fat in adipose tissue
Insulation-as a subcutaneous layer it reduces heat loss through the skin
Satiety value-when gastric contents containing fat enter the duodenum, the emptying time of the stomach is prolonged, postponing the return of hunger.