Based on the current understanding of human physiology, developed the modern theory of nutrition. According to her, for the health food person shall fully compensate the energy costs to build and the regeneration of tissue, to be balanced, not only on proteins, fats and carbohydrates, but also vitamins and trace elements.
Power supply system for each individual and depends on age, sex, presence of congenital or acquired diseases, etc. factors determining the human metabolism.
Food enters the body consists of several components: a useful ballast and harmful. Beneficial ingredients (nutrients) are proteins, fats and carbohydrates.
Proteins (proteins) is the main “building material” for the cells in our body, but that their functions are not limited to, of them are synthesized hormones, enzymes, cell signaling and other chemicals, ensuring the most vital processes in the cell and the metabolism in the body. Under the action of digestive enzymes break down proteins into amino acids it releases energy in the amount of 16.7 kJ (4.3 kcal). Amino acids are the synthesis of essential substances, energy for biosynthesis is required not less, and sometimes more than was allocated in the splitting, so the body uses proteins as an energy source only as a last resort.
The value of proteins depends on the amino acids serve their constituents, only proteins contain 20 amino acids including 8 indispensable – they are not synthesized by the body and must come from food. Animal proteins are more valuable than vegetable, almost not having in its composition of essential amino acids.
Fats (lipids) – energy suppliers, with them splitting it stands out much more – 38 kJ or 9.1 kcal. They perform other functions, for example, construction (cholesterol and others). From fat is formed subcutaneous adipose tissue, which ensures thermal insulation of the body.
Harm represent refractory fat (lamb, pork), and the excess of butter (more than 10-15 g/day), hidden fats in sausages, sausages, sausages.
A Healthy diet is a big role for polyunsaturated fatty acids (omega-3 and omega-6), they are contained in vegetable oil, fatty fish species, seafood, nuts (e.g., hazelnuts ).
Carbohydrates (saccharides) are another source of energy, the calorie, and protein have only 4 calories, but in contrast to fats, they are digested much easier, so are more preferred sources of energy. In addition to energy, carbohydrates have other functions, such as glucose (a carbohydrate), regulates osmotic pressure, other carbohydrates (oligosaccharides) are part of the cell receptors.
Divided carbohydrates, fast and slow. Healthy food concept involves the use of slow (polysaccharides: glycogen, starch, pectin etc.), not fast (oligo – and monosaccharides: glucose, sucrose, fructose, lactose, etc.) carbohydrates, which differ in the speed of digestion in the gastrointestinal tract and digestibility. Fast carbs, very sharply raise blood sugar, which in some cases can be dangerous for the body, and after that deposited “in reserve” that contributes to obesity.
The sum of all energy flow in the body with proteins, fats and carbohydrates, is called caloric intake. Excess caloric intake is the main cause of obesity and cardiovascular diseases, but no less danger and conceals its lack of calorie content, for example a paradox: fatty liver disease, provoking not only the excess fat, but diet hungry.
The calorie content varies widely from 1700 to 5000 kcal. City dweller, worker of intellectual labor spends about 2000-2300 calories.
Muscle burns calories, even at rest, it should be considered when determining the calorie content of their diet or aspire to it (if you want to lose weight).
Ballast substances (cellulose) does not bear the body’s energy value, but performs the no less important cleansing function, increases intestinal motility.
In addition to nutrients, the need of which ranges from tens to hundreds of grams, there are substances needed by the body in small and even very small quantities, but without them it is impossible to do is vitamins and minerals. They must do daily and in the required quantities.
A balanced diet
Impossible to compensate the energy consumption of the body with some nutrients at the expense of others, such as their cheapness or taste preferences – it causes imbalance in the body.
The ratio of consumption of protein:fat:carbohydrates should be 1:1:4 (in average), with a small energy cost, for example, sedentary work, a ratio of 1:0,8:3, with the hard work of 1:1:5.
It is considered that 1 kg of body weight, you need to consume 0.8-1 grams of protein. Children rate is higher 2-4 G.
The concept of diet includes adhering to a meals and intervals between them, the physiological rational in relation to frequency of meals and the proper distribution of the quantity and quality of food through techniques.
The optimal interval between meals is 4-5 hours, on this basis should be your diet, but at least 4 times.
Breakfast accounts for 25% of calorie daily diet;
for lunch 35%, afternoon snack or second Breakfast 15%;
for dinner 25% (no later than 2-3 hours before bedtime).
If you have a long working day, the number of meals increases to 6.
Smaller meals (6 or more times) are shown and in the presence of certain diseases, and healthy people nutritionists recommend to eat more often but small portions. In not distended the human stomach is part of food, about how much fits in two hands (if they connect a “boat”) that much, according to nutritionists, you should eat at one time.
Depending on season and lifestyle person needs 1.5-2 liters of fluid a day. Symptoms of dehydration appear when you use the 1st and less than a liter of water.