Fatty acids are the simplest lipids and consist of long hydrocarbon chains.
Fatty acids are a component of more complex lipids, they provide most of the calories from edible fats.
Fatty acids are classified based on the number of carbon atoms in the molecule (chain length). They can be saturated, i.e. Without double bonds. These include lauric (C12: 0), myristic (C14: 0), palmitic (C16: 0) and stearic (C 18: 0) acids. Monounsaturated fatty acids, such as oleic (C18: 1), contain one double bond. Polyunsaturated fatty acids, such as linoleic acid (C 18: 2), contain more than one double bond. Some of the polyunsaturated fatty acids, namely, linoleic and linolenic, can not be synthesized in the body, so they are referred to as essential fatty acids. They must enter the body with food. These acids are used to synthesize other polyunsaturated fatty acids with a long chain, which are of great importance in the synthesis of eicosanoids. Unsaturated fatty acids are also classified according to the position of the double bond, that is, omega-9 (Q-9, or n-9), omega-6 (Q-6, or n-6), omega-3 (Q-3, or n-3), based on the position of the first double bond from the methyl end group. In addition, these unsaturated fatty acids are also classified based on the isomeric configuration of the double bonds, namely, cis- and trans-, which determine the properties of these acids.
The type of fatty acid can affect the physical properties of fat, its absorption, absorption, metabolism, utilization and, finally, health.
In the American diet, approximately 80% of the total fat is provided by meat, fish, salads, fats, on which food is prepared and added to the dough, and dairy products. In addition, meat, poultry, fish, eggs and dairy products are the main sources of saturated fatty acids. Products from cereals, such as yeast bread, cakes, biscuits, greatly contribute to the consumption of mono- and polyunsaturated fatty acids. Fish and crustaceans are the main sources of polyunsaturated fatty acids with a long chain.
Dietary fats and vegetable oils are triacylglycerides (TAG), in which three fatty acids are esterified into glycerin with a predominance of a characteristic fatty acid, which affects the overall diet composition and the choice of diet. Fats and oils consist of many fatty acids, presented in proportions, characteristic for the corresponding fat or oil. Usually one or two fatty acids predominate in fat or oil. For example, linoleic acid accounts for 78% of fatty acids in sunflower oil. In addition, vegetable oils, except tropical coconut and palm oil, are the main sources of unsaturated fatty acids, and animal fats are sources of saturated fatty acids, therefore, the fatty acid profile in the diet can be changed only by replacing the fat source. In addition, biotechnology allows the production of fats and products with a specific composition of fatty acids, the so-called constructed products.
Dietary recommendations and fat intake
General dietary recommendations provide for total absorbed energy <30% due to total fat and <10% due to saturated fatty acids, and cholesterol intake <300 mg per day.
Several national surveys by various US organizations indicate that the total fat consumption of the population has decreased to about 34% of calories compared to 1990. Data show that only 18, 14 and 21% of men and 18, 18 and 25% of women at the age of 6-11, 12-19 and over 20 years old, respectively, received <30% energy from fats.