Health food Introduction n utrition

4. Where and how food is digested (anatomy of the digestive system, physiology of digestion)

The assimilation of food depends on the type of product and on how varied the diet is. Foods of animal origin are better digested, while the digestion of proteins is of primary importance. The proteins of meat, fish, eggs and dairy products are absorbed better than the proteins of bread, cereals, vegetables and fruits. The most important factor in proper nutrition is the variety of food. Monotonous food becomes boring and less digestible. When eating meat, bread and cereals, an average of 75% of the proteins contained in them are absorbed, and when vegetables are added, digestibility increases to 85–90%. Correct, sufficient heat treatment of products and their grinding significantly increase the digestibility of nutrients.

Dietincludes the following concepts:
1) the number of meals,
2) intervals between meals,
3) the distribution of daily caloric intake between individual meals. The most rational is four meals a day, which creates a uniform load on the digestive tract and ensures the most complete processing of food by digestive juices. Eating at the same time develops a reflex for the most active secretion of gastric juice at the set time. The distribution of the daily ration with four meals a day is made depending on the daily routine and established habits. In any case, the last meal should be at least 2-3 hours before bedtime. The most appropriate is the following distribution of the diet: breakfast - 25%, lunch - 35%, afternoon tea - 15%, dinner - 25%. When working on a night shift, 2-3 hours before work, dinner should be 30% of the daily ration and, in addition, meals are provided in the 2nd half of the night shift.
The temperature regime of food is also important for normal digestion. Hot food should have a temperature of 50–60 °, cold dishes - not lower than 10 °.
nutrition vitamin digestion rational
5. Fundamentals (principles) of rational nutrition

The human body obeys the laws of thermodynamics. In accordance with them, we formulate the first principle of rational nutrition: its energy value must correspond to the energy costs of the body. Unfortunately, this principle is often violated in practice. Due to the excessive consumption of energy-intensive products (bread, potatoes, animal fats, sugar, etc.), the energy value of daily rations often exceeds energy costs. With increasing age, there is an accumulation of excess body weight and the development of obesity, accelerating the onset of many chronic degenerative diseases.

The second principle of rational nutrition is the correspondence of the chemical composition of nutrients to the physiological needs of the body. Every day, in a certain amount and ratio, about 70 ingredients should enter the body, many of which are not synthesized in the body and therefore are vital. An optimal supply of these nutrients to the body is possible only with a varied diet. The maximum variety of nutrition determines the third principle of rational nutrition.
Finally, compliance with the optimal diet determines the fourth principle of rational nutrition. Under the diet refers to the regularity, multiplicity and alternation of meals. The diet, as well as the need for nutrients and energy, varies depending on age, physical activity. Compliance with these basic principles of rational nutrition makes it complete.
To achieve this goal, it is necessary to take into account:
The quality and energy value of the products used, in addition, the condition of their storage is of no small importance;
A method of cooking, which should provide both taste and nutritional properties of dishes, as well as their energy value;
Conditions, frequency and time of eating;
The amount and calorie intake of food per day
Changes in diet during periods of intense exercise.
Compliance with recommendations on rational nutrition is the main source of increasing the body's resistance to various harmful environmental influences and reducing a number of non-communicable chronic diseases.
Using these recommendations by 90% it will be possible to avoid the adverse effects of food on a healthier and more slender figure in general.
Normal body weight. Reasons for being overweight. Normalization of body weight by rational nutrition and means of physical culture.
There are different formulas for determining the optimal ratio of weight and height. But they are all conditional, since they do not take into account many other factors. Therefore, excess fat should be assessed not only by these ratios, but also by appearance, skin fold thickness, etc. With the same height and weight, one person may look full, while another may look completely normal.
It has long been no secret that how much a person weighs depends on how much energy (calories) enters his body with food and how much is consumed. If we eat more than we can expend, that energy is stored as fat. However, it is not only the nature or amount of food that matters, but also the regularity of its intake. Frequent erratic eating, as well as overeating at night, contribute to weight gain. As for physical work, it was noticed that thin people make more abrupt and “extra” movements than obese people, which means they spend more energy (this was even recorded on film). In addition, the psychological attitude to certain life situations is of great importance: whether we rush to do the cleaning (repair our favorite car) if we are in grief, or sit down at the TV with a bag of chips or a chocolate bar.
It turned out that oxygen consumption when performing the same physical work (that is, fat burning) in some obese people is less, that is, energy resources are spent more economically. It is believed that this should have contributed to the survival of primitive man.
Whether an adult is predisposed to obesity or not is influenced by nutrition during childhood and adolescence. If a child is overfed, his fat cells "adipocytes" will begin to multiply intensively. There will be more of them, which means there will be more “potential adipose tissue”. In infants, protein overfeeding is of great importance in this regard: an early transition to artificial feeding with the use of products containing a large amount of protein that is difficult to digest for a child - (cow's milk, cottage cheese).
Genetic factors also play a role. Studies have shown that relatives of an obese person are more likely to be overweight. And this is due not only to the peculiarities of metabolism, but also to the preference for certain products, lifestyle features adopted in these families or genetically determined. On the other hand, there are syndromes, one of the signs of which is obesity. Among them are Laurence-Moon-Biedl syndrome (obesity, underdevelopment of the genital organs, mental disorders, the presence of extra fingers, etc.), Prader-Willi (obesity, decreased muscle tone, underdevelopment of the genital organs, etc.). And the last - endocrine factors. For some reason, many believe that their excessive body weight is the result of the action of hormones. Obesity, indeed, occurs in some diseases of the endocrine system: hyperfunction of the adrenal cortex (syndrome and Cushing's disease) and hypofunction of the thyroid gland (hypothyroidism). At the same time, the distribution of fat in Cushing's syndrome is specific. Such people have thin arms and legs, a large saggy belly and a “fat” back. This is the so-called trunk type of distribution of fatty tissue. With hypothyroidism, there can also be obesity, but if these patients restore normal levels of thyroid hormones in the blood serum, then this is unlikely to end with anything more than a loss of a few kilograms.
Normalization of body weight is not an easy task and requires constant self-control on the part of a person who wants to lose weight. First of all, you need to create a sufficiently strong motivation and consistently implement the weight loss program.
The usual transition to a separate diet leads to the fact that a person loses from 5 to 15 or more kilograms of his own weight. Naturally, in people of short stature and low weight, these losses will not be as pronounced as in larger people.
As practice shows, being on a separate diet, a person greatly loses weight and looks thin. To prevent this from happening, you need to choose for yourself an individual diet, which is characteristic of an individual physique, age and season.
Even more dramatic changes will begin to occur if you eat natural fresh food, and not artificial, canned, refined, overcooked, etc. Only natural food is the most reliable guarantor of maintaining body weight and good health.
Each animal eats the type of food to which it is adapted. So the human body is adapted to the appropriate food. If he eats it, then everything is in order with his body weight. If he eats artificial food, strongly modified by heat treatment, purification, devoid of vital elements (vitamins, minerals, etc.), then body weight increases due to fat, and ligaments and bones weaken from a lack of the elements they need.
To maintain normal body weight and health, it is not recommended to take the following food.
• Foods containing too much salt. Salt retains water in the body and thereby increases the inert body mass.
• Sugar and products based on it: jams, jellies, marmalade, ice cream, sherbet, cake, fruit juices with sugar, soft drinks. Sugar for its absorption requires a mineral "binding", which is taken from the body's bone tissue, weakening it.
• Refined grain products in the form of flour and products based on it: white bread, rye bread with the addition of white wheat flour, biscuits, waffles, pasta, noodles, pasta, pies, buns. Refined grain, ground into flour, does not contain minerals (they are in the shell) and vitamins. As a result, it turns out that “vegetable fat” is consumed, which replenishes human adipose tissue. At the same time, minerals and vitamins are taken from the bones and tissues of the body for the absorption of starch.
• Fatty foods, saturated fats such as margarine and hydrogenated oils. You should eat less fried food.
• Smoked fish of any kind, smoked meat. As well as meat products of industrial production: sausages, smoked sausage, canned meat and fish.
You should especially avoid products that contain various kinds of substances that increase the shelf life of products and their presentation.
• Fat, fatty meat, preservatives - all these products contribute to the body's gaining inert body mass, which will weigh heavily on the spine, burden the heart, and slagging the tissues.
• Alcohol, tobacco, chocolate, sweets. The same applies to self-medication with various drugs. In addition to temporary relief and subsequent slagging of the body, they will not bring anything.
The abundance of toxins entering the body contributes to the fact that the body retains water to dilute them. As soon as we remove them, excess water disappears - body weight decreases.