Obesity is a chronic disease in which there is an accumulation of excess amounts of adipose tissue in the body.
Obesity is a chronic disease in which there is an accumulation of excess amounts of adipose tissue in the body. In men, obesity is considered to be the accumulation of adipose tissue of more than 20% of body weight, in women - more than 25%.
Obesity occurs due to a mismatch between the amount of energy supplied with food and energy, and the energy expenditure of the body. If the body expends less energy than it receives from food, excess energy accumulates in adipose tissue.
The causes of obesity are different:
appetite control disorders
The role of hereditary predisposition is large, but in any case, obesity occurs as a result of the patient's eating behavior. It is believed that the contribution of the hereditary factor in obesity is no more than 5%.
The reasons for the increase in the number of obese patients at the present time:
Availability of food. In developed countries, food is available, cheap, especially high-calorie, easily digestible foods. In order to get food, you no longer need to expend a lot of energy.
Violation of the power structure. Increased consumption of fats and carbohydrates with confectionery products, flour products, sweets, sugary drinks. At the same time, protein foods, fresh vegetables and fruits are not consumed enough.
Rapid intake and insufficient chewing of food. At the same time, the body does not have time to respond to a sufficient amount of food (the feeling of satiety does not have time to form) and food energy is absorbed excessively. In addition, the processing of poorly chewed food in the gastrointestinal tract slows down, which leads to an even more complete extraction of energy from food.
Plentiful food in the evening. At night, the synthesis of cholesterol in the body and the deposition of fats in the tissues increase, which is facilitated by a decrease in energy costs during sleep.
The energy received from food in modern conditions is not fully spent, which is facilitated by low physical activity, a sedentary lifestyle, mechanization of labor and other physical efforts (walking, climbing stairs). In this case, hypoxia occurs (insufficient supply of oxygen to the blood and, accordingly, to the tissues of the human body). Inadequate oxygen supply to adipose tissue delays the breakdown of fats.
Obese people resort to various diets that offer weight loss in the shortest possible time. But at the same time, no one thought at the expense of what processes inside the body weight loss occurs from a particular diet. In this paper, I want to consider the most common diets at the biochemical level and find out all the pros and cons of their effect on metabolism.
The substance entering the body contains chemical energy (the energy of intramolecular chemical bonds). This energy is converted in the body into the chemical energy of other compounds, as well as into thermal, mechanical and electrical energy. The main substances necessary for a full-fledged metabolism are proteins, fats and carbohydrates, since they are the main organic substances that make up the human body. It is to change the amount of consumption of foods containing these substances that various diets work.
The first diet that I would like to consider is the "Kremlin diet" or low-carb. The Kremlin diet requires limiting carbohydrate intake. The scientific explanation for this approach is that when the intake of carbohydrates is sharply limited - and they are the primary source of energy - it immediately begins to process the accumulated fat reserves, since the body needs energy for normal functioning. So, carbohydrates do not enter the body, fats are emulsified, then they undergo lipolysis, breaking down to glycerol and fatty acids. Fatty acids, in turn, undergo β-oxidation, due to which energy is generated for life.
After entering the cells, fatty acids are activated by the formation of acyl-CoA. This requires two energy-rich anhydride bonds of ATP. Activated fatty acids enter the mitochondrial matrix in the form of acylcarnitine, which is a transmembrane carrier.
Fatty acid degradation occurs in the mitochondrial matrix by an oxidative cycle of reactions, in which C2 units are sequentially cleaved off in the form of acetyl-CoA (activated acetic acid). Sequential cleavage of acetyl groups starts from the carboxyl end of the activated fatty acids each time between C-2 (α-atom) and C-3 (β-atom). Therefore, the cycle of degradation reactions is called β-oxidation.
For complete degradation of a long-chain fatty acid, the cycle must be repeated many times. The resulting acetyl-CoA can be transferred to oxaloacetate to form citrate, an intermediate metabolite of the citrate cycle.
Thus, even in the absence of carbohydrates, the process of formation of acytyl-CoA, which is the "fuel" for the formation of energy in the Krebs cycle, takes place.
In addition to the energy obtained from β-oxidation, fatty acids synthesize ketone bodies, which are needed by the body only in small quantities. In the blood of a healthy person, ketone bodies are contained only in very small concentrations (in the blood serum 0.03-0.2 mmol / l). In pathological conditions (in persons with severe diabetes mellitus, during fasting), the concentration of ketone bodies in the blood serum increases and can reach 16-20 mmol / l.
The term "ketone bodies" refers to acetoacetic acid (acetoacetate) CH3COCH2COOH, β-hydroxybutyric acid (β-hydroxybutyrate or D-3-hydroxybutyrate) CH3CHOHCH2COOH and acetone CH3COCH3. Ketone bodies are formed in the liver. After β-oxidation of fatty acids, not all of the formed acetyl-CoA goes to the tricarboxylic acid cycle, and a small part goes to the synthesis of ketone bodies. They are a source of energy for the muscles, kidneys, and possibly act as part of a regulatory feedback mechanism to prevent the emergency mobilization of fatty acids from fat depots. Acetyl-CoA, formed during the oxidation of fatty acids, is included in the tricarboxylic acid cycle under conditions when the breakdown of fats and carbohydrates is properly balanced. The inclusion of acetyl-CoA in the Krebs cycle depends on the availability of oxaloacetate for the formation of citrate. However, if fat breakdown predominates, the fate of acetyl-CoA is altered. This is explained by the fact that in the absence of carbohydrates or in violation of their use, the concentration of oxaloacetate decreases. During starvation or diabetes, oxaloacetate is consumed in the formation of glucose and therefore cannot condense with acetyl-CoA. Under such conditions, the pathway of acetyl-CoA metabolism deviates towards the formation of acetoacetate and D-3-hydroxy-butyrate, i.e. ketone bodies, which are secreted from the liver into the blood. The accumulation of ketone bodies in the blood leads to acidosis (decreased During starvation or diabetes, oxaloacetate is consumed in the formation of glucose and therefore cannot condense with acetyl-CoA. Under such conditions, the pathway of acetyl-CoA metabolism deviates towards the formation of acetoacetate and D-3-hydroxy-butyrate, i.e. ketone bodies, which are secreted from the liver into the blood. The accumulation of ketone bodies in the blood leads to acidosis (decreased During starvation or diabetes, oxaloacetate is consumed in the formation of glucose and therefore cannot condense with acetyl-CoA. Under such conditions, the pathway of acetyl-CoA metabolism deviates towards the formation of acetoacetate and D-3-hydroxy-butyrate, i.e. ketone bodies, which are secreted from the liver into the blood. The accumulation of ketone bodies in the blood leads to acidosis (decreasedblood pH and decrease in plasma bicarbonate). But such a serious manifestation with this diet is rarely observed, since for this it is necessary to “sit” on it for a long time.
PREMIUM CHAPTERS ▼
A serious consequence of carbohydrate deficiency is a decrease in blood glucose levels (hypoglycemia), to which the central nervous system is especially sensitive. There are weakness, drowsiness, dizziness, headaches, hunger, nausea, sweating, trembling in the hands. These phenomena quickly disappear after taking sugar. Since the "Kremlin diet" is based on the use of animal products, there is an excess of proteins in the body, leading to an overload of the liver and kidneys with its decay products, an overstrain of the secretory function of the digestive apparatus, an increase in putrefactive processes in the intestines, an accumulation in the body of nitrogen metabolism products with a shift in acid- ground state to the acid side. High-protein nutrition negatively affects patients with atherosclerosis. Too much animal protein (meat,
Vegetarianism is a diet that excludes or significantly limits the consumption of animal products. Among vegetarians, fruitarians stand out (they consider fruits and nuts to be natural human food), macrobiotics (grain products), lacto-vegetarians (they allow the use of milk and dairy products), and so on.
Rational in vegetarianism is the recognition of the high nutritional value of vegetables and fruits as valuable sources of vitamins, organic acids and minerals. Vegetable products are rich in fiber, which is necessary for the normal functioning of the intestines, the removal of toxic substances accumulating in it, and the removal of cholesterol from the body. Vegetarian diet is useful in diseases of the cardiovascular system. It has been proven that the number of heart attacks in vegetarians is 90% lower. Finally, vegetarian cuisine is more profitable from an economic point of view.
At the same time, when using only plant foods, the body's need for high-grade proteins is not met. Despite the significant content of proteins in some plant products, they are inferior, because. do not contain essential amino acids needed by the body. The last person receives only with products of animal origin (meat, fish, milk, eggs). In addition, plant proteins are less digestible.
With the predominance of plant products in the diet, first of all, there is a lack of three amino acids: methionine, lysine, tryptophan. Methionine has a lipotropic property, prevents obesity and accumulation of fat in the liver, plays an important role in the prevention of atherosclerosis. Lysine is necessary for growth and hematopoiesis. Tryptophan is important for growth and maintenance of nitrogen balance.
Some vitamins (B12, D) are found mainly in products of animal origin, therefore, with the predominance of plant foods in the diet, corresponding hypovitaminosis can be observed.
As you know, proteins are high-molecular organic substances, which are the main structural element of all cells and tissues, a plastic substrate for the growth and development of the body, regeneration processes. The lack of proteins leads to alimentary dystrophy, which is expressed in weight loss, since the human body cannot synthesize proteins from inorganic substances and begins to break down its own proteins, in particular skeletal muscle proteins. Protein deficiency leads to slower growth and development in childhood and adolescence.
Proteins are enzymes and hormones, catalyzing metabolic processes and performing a regulatory function. Thus, with a lack of proteins, the normal course of metabolic processes is disturbed.
Immunoglobulins (antibodies) are proteins and perform a protective function. A significant protein deficiency can lead to immunosuppression, a decrease in the reactivity and resistance of the body.
Protein is of great importance in the activity of the central nervous system. The lack of protein in food leads to a decrease in attention, performance, and so on.
Lack of protein in food leads to a decrease in the barrier function of the liver, changes in the endocrine system.
Animal proteins are more complete. The completeness of proteins is determined by the content of all essential amino acids in them, in particular essential amino acids, which must be present in the diet, since they are not synthesized in the body from other amino acids. Essential amino acids include lysine, tryptophan, histidine, isoleucine, leucine, methionine, valine, threonine, phenylalanine, and arginine with histidine for children.
Complete animal proteins are found in the greatest amount in the yolk of a chicken egg, meat, fish, milk, dairy products (cheese, cottage cheese). In vegetable products, complete proteins are found in soy, to a lesser extent in beans, potatoes, rice, oatmeal, and buckwheat. Bread, peas and other cereals mainly contain defective proteins.
Fats are the most valuable energy material. They are part of the cells, provide absorption from the intestine of a number of minerals and fat-soluble vitamins, the main component of the cell membrane. From this definition, we can conclude that a lack of fat leads to the development of defective cells in the body, since the proper construction of cell membranes is impossible, and the absorption of fat-soluble vitamins will become impossible. There will be a lack of energy in the body.
The predominance of plant foods in the diet leads to an excess of fiber, hence the overload of the intestinal microflora. There will also be an excess of carbohydrates.
Thus, strict vegetarianism can hardly be recommended as a permanent diet.
The effect of mono-diets on metabolism
The essence of mono-diets is that only one product is consumed, it can be rice, kefir, various fruits, juices. But their use for a long time can adversely affect the state of health.
Rice - its excess can cause thickening of bile, and, as a result, the formation of stones in the gallbladder. Lack of protein leads to a decrease in the level of hemoglobin in the blood. There are few vitamins in rice, and taking chemical vitamin preparations as a compensation increases the appetite, and, consequently, the feeling of hunger.
Cottage cheese is a big protein load. Its excess disrupts calcium metabolism: if there are problems with the gastrointestinal tract, due to impaired protein absorption, calcium will also be poorly absorbed, and this is harmful to health.
Kefir is the absence of carbohydrates. Kefir disrupts intestinal motility, causing either constipation or loose stools.
Vegetable oil - its excessive consumption for the purpose of "cleansing the intestines" can cause the formation of stones in the bile ducts.
Pomegranate - consumption of more than 1.5 liters of pomegranate juice per day increases the risk of kidney, gall and bladder stones by 48%.
Carrots - excess causes "carrot hepatitis", which is manifested by yellowing of the skin.
Apples are just carbs. The lack of protein causes changes in the endocrine system, in the case of a stubborn diet, a woman may stop menstruating. The conduction of nerve impulses and, in general, higher nervous activity suffer from a lack of protein.
Watermelons - due to the complete absence of fat in them, fat-soluble vitamins will not be absorbed. With a lack of fat, the renewal of body cells is also disrupted.
Bananas - can cause stool retention. Due to impaired motility of the gastrointestinal tract, the amount of toxins in the body increases. An excess of easily digestible carbohydrates raises blood glucose levels, causing hyperglycemia.
Raw vegetables are a "hit" on the enzymatic systems of the body, depletion of the liver and pancreas.
Juices - having a stimulating effect on appetite, increase the feeling of hunger, which already torments those who want to lose weight. Due to the lack of fiber, the intestines suffer. The acids contained in juices irritate the gastric mucosa.
Dry eating - with a limited amount of fluid, it causes blood to thicken, and thereby increases the likelihood of blood clots. Due to the lack of fluid, it is difficult for the kidneys to remove decay products.
To avoid problems with weight and do not have to resort to the “help” of various diets, you should eat rationally.
Rational or balanced nutrition is the process of entering the body and assimilation of substances necessary to cover energy and plastic costs, build and renew tissues and regulate functions. For normal growth, development and maintenance of life, the body needs proteins, fats, carbohydrates, vitamins and mineral salts in the right amount.
The principles of rational nutrition are:
1) compliance of the energy value of food entering the human body with its energy consumption;
2) the intake of a certain amount of nutrients into the body in optimal ratios;
3) correct diet;
4) variety of food products consumed;
5) moderation in food.
According to the formula of a balanced diet, the ratio of proteins, fats and carbohydrates should be 1: 1.2: 4.6. Then metabolic processes in the body will proceed stably, nutrients will be rationally used, and there will be no conditions for metabolic disorders.