The subject of nutritional physiology is the determination of the body's need for nutrients necessary as sources of energy for life processes, continuous renewal of chemical structures of cells, tissues, and the function of complex physiological systems. The physiology of nutrition studies the conditions for the optimal assimilation of chemicals by the body, which is influenced by age, gender, state of health, nature of work, climate, diet, etc., as well as methods of technological processing of raw materials and products, changes in their composition during storage and a number of other factors.