Nutritional value of Fats and Fats Products

Nutritional value of Fats and Fats Products
Dietary fat provides a highly concentrated form of energy for the human body. On a gram for gram basis, lipids contain more than twice energy of either carbohydrate or protein (lipids, 9.3kcal/g; carbohydrate and protein, 4.1kcal/g). Ethyl alcohol, with 7.0kcal/g, almost approaches the energy value of fat.

In United States, the average dietary intake of fat has increased from 124 g/person/day in 1910 to 163 g/person/day at present. About two-thirds of the dietary lipids come from animals, and the remaining from vegetables. In addition to serving as an important energy source, dietary fat serves as a carrier for fat soluble vitamins and provides essential fatty acids. These needs can be met by a diet containing 15-25 g of food fats.

Since the discovery of the essential fatty acids by Burr and Burr (1929), numerous studies have demonstrated that probably all animal species may develop symptoms of essential fatty acid deficiency of raised on fat free diets. Weanling rats on a fat free diet grow poorly, showing deficiency signs such as dermatitis. Poor reproduction, lowered caloric efficiency, impairment of lipid transport, and decreased resistance to stress. When linoleic acid is present in the diet, the symptoms associated with fat deficiency do not develop. Arachidonic acid and linoleic acid have also been show to prevent the symptoms. Undoubtedly, mammals are unable to synthesize linoleic acid and linolenic acid, both of which contain unsaturated double bonds. Since these two acids cannot be synthesized in mammalian tissue, but are required the diet, they are called essential fatty acids.
Nutritional value of Fats and Fats Products