1. As a source of energy and energy reserve:
Fat serves as a concentrated source of energy. Each gram of fat yields 9 calories of energy (twice the double amount yielded by carbohydrates and protein). Any excess of energy is stored in the form of fat or adipose tissue. Adipose tissue which consists mainly of triglycerides is stored under the skin, around the organs and in the abdominal Cavity.
2. Satiety Value:
Fat tends to leave the stomach relatively slowly, being released approximately 3Vz hours after ingestion or taking of food. This delay in the emptying time of the stomach helps to delay the onset of hunger pangs and contribute to a feeling of satiety after a meal.
3. Carrier of fat-soluble vitamins:
Fat carries fat-soluble vitamins like A, D, E, and K into the body and help in the absorption of these vitamins.
4. Source of essential fatty acids:
The body cannot synthesize certain fatty acids and has to be supplied from the diet. These are called as the essential fatty acids linoleic acid, a poly unsaturated fatty acid, which is necessary for the growth of the young and maintenance of a healthy skin.
Fat contributes a lot to the palatability of food as appreciated by those who exist on a low-fat diet. Many substances responsible for the flavors and aroma of food are fat soluble. It has also been suggested that fat in the diet stimulates the flow of digestive juices.
Deposits of fat beneath the skin serve as insulating material for the body, protecting it against shock from changes in environmental temperature.
7. Body regulator:
Fat as an essential constituent of the membrane of each individual cell, helps to regulate the uptake and excretion of nutrients by the cell.
8. Protection of vital body Organs:
Fat deposits that surround certain vital organs serve to hold them in position and shield them from physical shock and injury to the kidneys and heart are protected in this way.