## 2 Materials and Methods
### Anthropometric and Somatic Measurements  
Body composition was analyzed by multi-frequency bioelectrical impedance analysis (MF-BIA) using the device InBody 970 (Biospace Co., Ltd., Seoul, Republic of Korea), which measured the impedance of five body segments at 1, 5, 50, 250 and 500 kHz and 1, 2 and 3 MHz. All measurements were performed under strictly standardized conditions using the same bioimpedance device. The measurements were performed by one trained person to avoid inter-observer errors. Each volunteer was measured twice, and if the results did not match and the differences were >1%, a third measurement was performed, and the mean of the obtained values was definitively used for the study. The technical error of measurement (TEM) was 0.68%. The volunteers were instructed about the procedural act and the risks of the MF-BIA method, which include pregnancy or having a pacemaker or other cardiac device. The participants signed an informed written consent as well as consent for the processing of personal data using the Lookin'Body 3.0 software (InBody Co., Ltd., Seoul, Republic of Korea). Before the measurement, the participants were asked to exclude and refrain from drinking large amounts of water, not to consume alcohol 24 h before testing, to avoid food with a high sugar, salt or fat content for 12 h before testing and to refrain from intense physical activity for at least 12 h beforehand.  
Body height (H) was measured using a professional electronic altimeter BSM370 (InBody Co., Ltd., Seoul, Republic of Korea), which automates measurement performance and eliminates human errors (error range for height \(\pm\)0.1 mm). The altimeter is directly connected to the InBody 970 device, which facilitates the transfer of the obtained data. The body height was measured in the traditional upright position with the head in the Frankfurt plane. Height was automatically measured from the feet to the highest point of the head.  
The bioimpedance measurement was performed under precisely defined conditions: the person was only in light clothing and with an empty stomach after using the toilet.  
The MF-BIA method was used to directly obtain the following data: basal metabolic rate (BMR, kcal); body weight (BW, kg); waist circumference (WC, cm); hip circumference (HC, cm); chest circumference (CHC, cm); arm muscle circumference (AMC, cm); fat-free mass (FFM, kg); skeletal muscle mass (SMM, kg); body fat mass (FM, kg, %); visceral fat area (VFA, cm\({}^{2}\)); intra-/extracellular and total body water (ICW, ECW, TBW, L).  
Body mass index (BMI), the waist-to-hip ratio (WHR) and the waist-to-height ratio (WHtR) were calculated according to standard formulas [20; 21; 22; 23]. We calculated the visceral adiposity index (VAI) using the formula for women [WC/36.58 + (1.89 \(\times\) BMI)] \(\times\) (TG/0.81) \(\times\) (1.52/HDL-C), where TG represents triglycerides and HDL-C represents high density lipoprotein cholesterol [24]. To calculate the body adiposity index (BAI), we used the formula [hip circumference/height\({}^{1.5}\)]--18 (%) [25]. Fat mass (kg), fat-free mass (kg) and skeletal muscle mass (kg) were taken to calculate the fat mass index (FMI, kg/m\({}^{2}\)), fat-free mass index (FFMI, kg/m\({}^{2}\)) and the skeletal muscle mass index (SMMI, kg/m\({}^{2}\)) as fat mass (kg) divided by square of the height (m\({}^{2}\)) or fat-free mass (kg) divided by sthe quarse of the height (m\({}^{2}\)) or skeletal muscle mass (kg) divided by the square of the height (m\({}^{2}\)). A body shape index (ABSI) was defined by WC/(BMI\({}^{2/3}\)\(\times\) height\({}^{1/2}\)) [26].  
Systolic and diastolic blood pressure was measured three times using a sphygmonometer OMRON M7 Intelli IT with AFIB (OMRON Healthcare Co., Ltd., Shiokoji Horikawa, Shimogyoku, Kyoto, Japan) with an accuracy of \(\pm\)3 mmHg of the measured value. The resulting average value of three measurements was used for the purposes of the study.