BALANCED FOOD — the food providing an organism with feedstuffs necessary for it in optimum ratios.
S.'s concept of the item is developed on the basis of scientific research in the area food (see) is also expression sovr. ideas of quantitative and qualitative features of processes of assimilation of food. According to this concept optimum life activity of a human body depends on observance of a certain relationship between various factors of food, each of to-rykh plays a specific role in a metabolism (see. Metabolism and energy ).
The problem of adequacy of food of the person to his requirements began to be investigated 19 at the end — the beginning of 20 century. By this time the chemical structure was generally studied foodstuff (see), irreplaceable components of food are open and basic researches of processes of digestion, absorption and assimilation of feedstuffs in an organism of animals and the person are conducted.
In development of the concept of S. of the item which is a basis of scientific ideas of needs of the person for feedstuffs, the big merit belongs to the Soviet scientists. In the 30th 20 century the group of scientists under the leadership of M. N. Sha-ternikova, P. N. Diatroptov and O. P. Molchanova received, generalized and published materials about the needs of a human body for the main feedstuffs. In 60 — the 70th under the leadership of A. A. Pokrovsky the basic researches which were a basis for a formulation and development of the concept of S. of the item were conducted.
A basis of the concept of S. of the item is existence of correlative dependence between digestion of food and extent of balancing of its chemical structure. A. A. Pokrovsky showed interrelation of the concept of S. of the item with the solution of the major practical problems of justification fiziol. norms of food, development of specialized products and diets. Influence of the concept of S. of the item on many important industries of the national economy, including on planning of the sphere of production of food stuffs, including research of new sources of protein is shown them in the book «Role of Biochemistry in Development of Science about Food» (1974) (see. Proteins of one-celled ). On the basis of S. the item proved the integrated circuit of definition of nutrition value of food stuffs, the principles of new rational approaches are created in to lay down. food (see. clinical nutrition ), standards of need of the person for feedstuffs (a formula C. of the item) are developed and new ways of researches in the field of biochemistry, physiology are planned and hygiene of food (see).
S.'s concept of the item is a result sovr. ideas of all sum of exchange reactions of substances in an organism, to-rykh are resulted by interconversions of one substances in others. Special attention at the same time is paid to irreplaceable components of food (to feedstuffs, to-rye cannot be formed in an organism) — irreplaceable to amino acids (see), polyunsaturated to fatty acids (see), being a part of fats, to vitamins (see) and to mineral substances (see).
In a diet of almost healthy person at average values of his energy expenditure the ratio is optimum proteins (see), fats (see) and carbohydrates (see), close to 1:1:4,5. It promotes the maximum satisfaction of energy and plastic demands of a human body. However during the strengthening of energy expenditure and increase in this regard the general caloric content of a diet of protein in it should reduce percentage, increasing amount of fats and carbohydrates. 12 — 13% of the general caloric content of a diet, on a share of fats — 30 — 50% shall fall to the share of proteins. At hard physical work protein content in a diet can be reduced to 11% of the general caloric contents (see).
Also the optimum ratio in food protein of amino acids is important. Protein, to-ry would contain all irreplaceable and replaceable amino acids in a ratio, optimum for food, or so-called ideal protein, in the nature does not meet. However proteins of animal origin (meat, fish, a bird, eggs, milk) contain all irreplaceable amino acids in the ratio, near optimal (so-called complete proteins). Phytalbumins in the vast majority are defective since contents in them is much lower than one, two or more irreplaceable amino acids, than in ideal protein. E.g., in proteins of wheat and consequently and proteins of white bread, contain insufficient quantity of a lysine (almost twice lower than optimum), threonine, from a leucine and valine; proteins of soy are characterized by the reduced content of methionine and threonine; in proteins of sunflower the quantity of a lysine (twice in comparison with ideal protein), methionine and threonine is lowered.
Knowledge of optimum ratios of amino acids in a diet allows to estimate the actual food of the population and to plan ways of its rationalization, and also to establish standards of need for protein depending on its amino-acid structure.
Biological activity of the mix of proteins used for food of the population of the USSR is equal to about 70% if to take the biological value of ideal protein for 100%. The daily need of a human body for protein depends on its quality: the less full are the consumed proteins (i.e. the more they differ from ideal protein), the above there has to be this norm, and, on the contrary, the consumed proteins to ideal are closer, the this norm shall be lower (theoretically apprx. 57 g of ideal protein on average on one person).
Fats shall average 33% of the general caloric content of a diet with differentiation on climatic zones: for the southern regions of 27 — 28%, for northern — 38 — 40%. The fullest are vegetable oils (see. Vegetable oils ), since they contain in a significant amount polyunsaturated fat to - you, belonging to irreplaceable feedstuffs, and also the phospholipids necessary for cell renewal and intracellular structures. It is recommended that vegetable oils made not less than 30% of total quantity of fats in a diet of the person. Polyunsaturated fat to - you are a part of cellular covers, intracellular membranes and are used by an organism for synthesis prostaglandins (see). Contents linolic acid (see) in a diet of the healthy person shall make 4 — 6% of the general caloric content of a diet.
In a carbohydrate part of a diet of the person there have to be at a significant amount ballast substances, or the so-called food fibers consisting of cellulose or hemicellulose. These fibers are not digested in went. - kish. a path, but promote its normal functioning, and also can occlude nek-ry toxins, interfering with their absorption in intestines (see. Cellulose ).
For prevention obesity (see), a diabetes mellitus (see. diabetes mellitus ), caries of teeth (see. Caries of tooth ) and some other diseases it is recommended that contents mono - and dpsakharid in a daily diet of the person did not exceed 50 — 100 g; it is important that this quantity was evenly distributed on separate meals that allows to avoid excess load of cells, to the sekretiruyuena insulin (see) and to prevent a possibility of an overstrain and wear of the mechanism of formation of insulin.
In maintenance of health, working capacity and longevity the great value belongs to balance of vitamin and mineral composition of a diet. A set of foodstuff with inclusion of enough vegetables, fruit, bread and milk, as a rule, satisfies needs of the person for all vitamins and mineral substances necessary for it. However in vegetables, fruit and other food stuffs in process of their storage the content of vitamins steadily decreases. These losses, especially during the winter and spring periods of year, shall be compensated by reception of vitamins (see. Vitamin drugs ) in the quantities corresponding to a formula C. of the item.
As a result of a lack of the protein of a daily diet caused by shortage of foodstuff, especially in combination with a lack of its general caloric content of an organism processes of updating and protein synthesis are broken, its resilience to various influences sharply decreases. At long proteinaceous and caloric insufficiency dystrophy develops (see. Nutritional dystrophy ).
Insufficient receipt with food of one or several vitamins leads to development corresponding hypo - or avitaminosis (see. Vitamin deficiency ), insufficient intake of mineral substances — to emergence adverse specific to disbolism a wedge, symptoms.
Quite often disturbance of a formula C. of the item is result of excess consumption of separate groups of foodstuff and is combined with the general redundancy of food, leading to development of a number of diseases. Among other diseases caused by disturbance of a balanced diet and metabolism obesity is high on the list. Direct dependence between development of obesity and increase in caloric content of a diet in connection with the increased content in it of fats and carbohydrates is established. Caloric content of a daily diet at a significant amount of patients with obesity reaches 5000 — 6000 kcal, in some cases 10 000 kcal, i.e. several times exceeds energy demands.
Excess consumption of proteins is risk factor for development of damages of a liver and, especially, kidneys. Diets, protein-rich animal origin, contain, as a rule, significant amounts nucleinic to - t. Since an end product of exchange of these acids in a human body is uric to - that, the strengthened consumption of foodstuff of animal origin leads to accumulation of this to - you in bodies and fabrics and to development gouts (see).
Excess consumption of the fats of animal origin containing a significant amount saturated fat to - t, creates the conditions favoring to developing of obesity, is risk factor of development atherosclerosis (see) and coronary heart disease (see).
Excess consumption of soluble carbohydrates (mono - and disaccharides) promotes developing of caries of teeth, is risk factor of development of a diabetes mellitus. The excessive use of vitamins is not recommended because of possible development hypervitaminoses (see). For nek-ry mineral substances (e.g., gland, copper, zinc, fluorine, etc.) not only the minimum quantities of their presence at foodstuff, but also the upper bounds are established, for to-rymi their toxic action begins to be shown.
The principle of balance of food shall be considered at catering services at catering establishments, in a dignity. - hens. conditions, hospitals.
Bibliography: Pokrovsky A. A. Fi-ziologo-biokhimicheskiye bases of development of products of baby food, M., 1972, bibliogr.; it, the Role of biochemistry in development of science about food, M., 1974; about N e, Food and a disease, Vopr. food, No. 1, page 18, 1976, bibliogr.
V. A. Shaternikov.