1. The main function of fats in the body is to provide energy: By supplying energy, fats save proteins from being used for energy and allow them to perform their more important role of building and repairing tissues. Fats on oxidation provide almost twice as much energy as that given by carbohydrates.
The fats provide on oxidation about 37 kJ of energy per gram as compared to 17kj of energy per gram of carbohydrates. Fats yield more energy than carbohydrates because fats contain less percentage of oxygen and higher percentage of carbon and hydrogen as compared with carbohydrates.
Fats can also be stored in body for subsequent use. When we consume food which has more energy than is required by the body for performing various functions, the excess food is deposited under our skin in the from of subcutaneous fat.
2. In addition to supplying energy, fats also help in forming structural material of cells and tissues such as the cell membrane.
3. Fats also carry the fats soluble vitamins A, D, E and K into the body and help in the absorption of these vitamins in the intestines.
4. Some fats supply essential fatty acids.