FOOD METABOLISM AND OBESITY. REPORT 1 (CONSUMPTION AND DEPOSITION)

The high prevalence of overweight and obesity has become an international social problem. In Russia, every fourth woman and every fifth man is overweight.
Obesity is a consequence of an imbalance between intake and consumption of organic food. There are two distin-guishable causes of overeating - hereditary metabolic disorders and everyday hyperphagia. The main cause of obesity in modern humanity is everyday hyperphagia.
Obesity is an increase in the number and size of fat cells – adipocytes – in the human body. An increase in the number of cells is accompanied by an increase in the number of capillaries and cholesterol. To contain 1 kg of adipocytes, 100 km of capillaries are required, and 10 kg of adipocytes contain 25 g of cholesterol. In people with a high body mass index, each kilogram of fat requires 5.4 kcal/day. Obesity is a cause of hypertension, atherosclerosis, myocardial infarction, abnormal lipid levels, and type 2 diabetes.
Attention is paid to the role of acetyl-CoA, which in the catabolic cycle of proteins, triglycerols and glucose is a common intermediate that can participate in energy and plastic metabolism. The heterogeneity of liver cells has been shown in terms of their ability to store glycogen and participate in gluconeogenesis.
In the process of intake and consumption, food organics are first deposited in the form of glycogen, triglycerols and proteins. The consumption of deposited substances is controlled by the basal metabolism, thermogenesis and psy-chophysical activity of the individual. The share of basal metabolism accounts for 50–70 % of the total consumption of matter and energy. In this case, the expenditure of matter and energy on the basal metabolism occurs automati-cally. The primary task is the supply of oxygen, the work of the heart, the work of the kidneys and tens of hundreds of metabolic reactions are carried out without our conscious participation.
Under conditions of regular and frequent nutrition, the needs of basal metabolism are provided by glycogenolysis and glycolysis. Under conditions of fasting and physical activity, triglycerols become in demand, which, through hydrolysis and subsequent oxidation of fatty acids, are converted into acetyl-CoA and used in the tricarboxylic acid cycle. Under conditions of regular, excess nutrition and low physical activity, adipocyte triglycerols are in demand by the body only for basal metabolism.

1. Nelson D, Cox M. Lehninger's Fundamentals of Biochemistry. in 3 volumes. T. 2. Bioenergetics and metabolism. Moscow: Knowledge Lab; 2022:636 (In Russian).

2. Velkov V.V. Dead loop of free fatty acids. Chemistry and life. 2009;(2):46-49 (In Russian). URL: https://hij.ru/read/4753 [accessed: 26.10.2023].

3. Global Obesity Observatory. URL: https://www.worldobesity.org/rankings [accessed: 26.10.2023].

4. Nanditha A., Ma R.C., Ramachandran A. et al. Diabetes in Asia and the Pacific: Implications for the Global Epidemic. Diabetes Care. 2016;39(3):472-485. https://doi.org/10.2337/dc15-1536

5. Newssbaum R.L., McInnes R.R., Willard H.V. Medical genetics. M.: GEOTAR-Medic; 2010:620 (In Russian).

6. Nelson D, Cox M. Lehninger's Fundamentals of Biochemistry. in 3 volumes. T. 1. Fundamentals of biochemistry, structure and catalysis. Moscow: Knowledge Lab; 2020:749 (In Russian).

7. [Physiology of the endocrine system. Ed. Griffin J. and Ojeda S. M.: BINOM, Knowledge Lab; 2008:496 (In Russian).

8. Mayboroda A.A. Molecular basis of lipidology. Irkutsk: ISCCT; 2023:119 (In Russian).

9. Elliot W., Elliot D., Biochemistry and Molecular Biology. M.: Publishing house of the Research Institute of Biomedical Chemistry of the Russian Academy of Medical Sciences; 1999:372 (In Russian).

10. Sabine J.R. Cholesterol. New York:Marcel Dekker; 1977:489.

11. Alberts B., Hopkin K., Dagonson A. et al. Fundamentals of molecular biology of the cell. M.: Laboratory of knowledge; 2023:796 (In Russian).

12. Koolman J., Roehm K.-H. Visual biochemistry. M.: Laboratory of Knowledge; 2019:509 (In Russian).

13. Mayboroda A.A. Structural and functional organization of a biological system. Siberian medical journal (Irkutsk). 2006;(7):95-97 (In Russian). URL: https://cyberleninka.ru/article/n/strukturno-funktsionalnaya-organizatsiya-biologicheskoy-sistemy [accessed: 26.10.2023].

14. Usynin I.F., Panin L.E. Mechanisms of formation of phenotypic heterogeneity of hepatocytes. Biochemistry. 2008;73(4):453-468 (In Russian). URL: https://biochemistrymoscow.com/ru/archive/2008/73-04-0453 [accessed: 26.10.2023].