Food fats along with whitewash and carbohydrates are the main sources of energy for the human body. Fats are also used by the body for plastic purposes. Fatty acids are part of cell formations – membranes, hormones, nerve tissue.
Fats, their role in human nutrition, norms of consumption of fats, the content of digestible substances in dietary fats, cholesterol.
Forming complex compounds with proteins, fats promote cellular metabolism. A heterogeneous class of substances belongs to fats. Simple fats are made up of glycerol and fatty acids. The bulk of food fatty acids are part of more complex fats, mainly triglycerides and phosphatides. Some of the fatty acids are synthesized in the body and are indispensable for its life..
Norms of fat intake in human nutrition.
The daily rate of fat intake for a middle-aged person is close to 100 g per day, which is about 30% of the total calorie content of food. At the same time, vegetable fats should account for 20-30%, i.e. 20-30 g. A similar ratio of fats of different nature is necessary in connection with the content in vegetable fats of such essential polyunsaturated fatty acids as linoleic and linolenic.
I must say that the norms of fat intake are set depending on climatic conditions. In the middle climatic zone, the fat content should be 30%, in the northern zone – 35%, in the southern – 25% of the total calorie intake.
The biological value of fats in human nutrition.
The biological value of fat is determined not only by its high calorie content, but also by the content of essential polyunsaturated fatty acids – linoleic, linolenic, arachidonic, and a number of fat-soluble vitamins. Including vitamins A, D, E. In the process of digestion, fats play the role of vitamin carriers. In case of violation of the processes of digestion and absorption of fats, the intake of fat-soluble vitamins stops in the body.
Polyunsaturated essential fatty acids regulate fat metabolism, lower blood cholesterol. That is, they are essential in the prevention of atherosclerosis, help strengthen the walls of blood vessels, protect the liver from obesity. When these acids are deficient in the diet, significant health disorders are noted.
The normal development of the growing organism, the structure and functions of cell formations (membranes) are disrupted, the condition of the skin worsens. The human need for essential polyunsaturated fatty acids is 2-6 g per day, in old age this norm can be increased to 10-15 g.
The main sources of linoleic acid.
The main sources of linoleic acid are vegetable oils, especially sunflower, corn, soy and cottonseed. They comprise about 50% linoleic acid, most of all in peanut butter – 73%. Much less of this acid is found in animal fats and least of all in butter.
The main sources of arachidonic acid.
Arachidonic acid, the most valuable biologically, is found in small amounts in some animal fats. In pork fat, in butter. The most significant amounts of arachidonic acid are found in fish oil and in some varieties of fish: mackerel, horse mackerel, notothenia, halibut. The body’s need for this acid is satisfied mainly due to its formation from linoleic and linolenic acids. For synthesis, an adequate supply of the body with pyridoxine (vitamin B6) is necessary.
The content of digestible substances in food fats (per 100 g of product).
Complex Edible Fats.
More complex dietary fats include phosphatides. They contribute to good digestion and normal fat metabolism. The most common phosphatide is lecithin, which contains choline. These substances interfere with the deposition of fat in the liver. Unrefined vegetable oils, eggs, sour cream, cream and other products are sources of phosphatides..
Fats supply the body with biologically valuable fat-like hydrocarbons – sterols. In the human body, the first place among them is unsaturated alcohol cholesterol, which plays the role of a key intermediate in the synthesis of other sterols (steroids). In addition, it performs other physiological functions, being an integral part of cell membranes and tissues..
In the body, cholesterol is easily synthesized from the oxidation product of carbohydrates and fats – activated acetic acid. Therefore, its content in tissues depends not only on food intake, but also on the intensity of synthesis and decay in the body. In a healthy person, these processes balance each other. In old age, the balance is often disturbed, less cholesterol is destroyed than it comes with food or is synthesized in the body.
Cholesterol content per 100 grams of product.
However, the consumption of cholesterol-rich foods by older people is not prohibited. It is not recommended only to abuse them. It is necessary to include a ration daily along with animal fats, vegetable oils. Polyunsaturated fatty acids of oils accelerate cholesterol metabolism and reduce its level in the blood, and the sterols contained in them slow down the intake of food cholesterol from the intestines into the blood.
It is advisable to use fruits and vegetables in your diet whenever possible. Fiber and pectin contained in them contribute to the removal of significant amounts of cholesterol from the body. Cholesterol is found in all animal products. Most of all in products such as brains, hearts, eggs, liver, butter and others.
Based on materials from the book Homemade Travel Equipment.