[Body composition and basal metabolic rate in overweight and obese patients]

Abstract

Diet therapy is a key moment in the treatment of patients with obesity. The energy value of the diet must directly depend on the daily energy expenditure. It is extremely important for a specialist who determines a diet for a patient, using an individual approach, to most accurately calculate daily energy expenditure. On the one hand, the calculation method should be as accurate as possible, on the other hand, it should be simple and economically affordable. The aim of the study was to evaluate the body composition in patients depending on gender and body mass index and to identify the optimal method for calculating the basal metabolic rate (BMR) in patients with various degrees of obesity. Material and methods. The study included data from 338 men aged 39.0±11.9 years and 847 women aged 44.0±12.5 years. The study of the body composition was carried out by the multi-frequency bioelectrical impedance analysis on the analyzer "InBody 770", which simultaneously provides information on the BMR, calculated taking into account the composition of the body according to the Ketch-McArdle formula. The BMR was also calculated using the Mifflin-St. Jeor formula and the results were compared. Results. In men and women, with an increase in body weight, an increase in skeletal muscle mass is noted, which entails an increase in the BMR. The BMR, calculated by the formula that does not take into account the volume of the main body energy-consuming tissues, differed from that calculated by the formula that takes into account the value of metabolically active components of the human body composition, towards an increase in men with obesity of class 2 and class 3 degrees, by 141 kcal and by 294 kcal, respectively, in women with obesity class 1 - by 81 kcal, class 2 - by 139 kcal, class 3 - by 262 kcal. Conclusion. When conducting primary diagnostics on an outpatient basis in patients with overweight and obesity, along with simple anthropometry, it is necessary to perform a body composition study. The calculation of the BMR as a component of daily energy expenditure should be carried out taking into account the characteristics of the body composition. If it is not possible to conduct a bioelectrical impedance study and accurately calculate the BMR, the results obtained during this research can be used: BMR in men with obesity of the class 1 - 18.5 kcal/day kg body weight, with obesity of the class 2 - 16.6 kcal/day kg body weight, with obesity class 3 - 14.6 kcal/day kg body weight; BMR in women - respectively 16.7, 15.0 and 13.5 kcal/day kg body weight.

Keywords: basal metabolic rate; body composition; fat mass; obesity; skeletal muscle mass.