2.4. Basal Metabolic Rate (BMR)

We used the indirect calorimetry method to measure the BMR. Each measurement took place after a 12-h fasting period by using the Cortex Metalyzer 3B equipment (Cortex Medical, Leipzig, Germany) the MetaSoft 3 software (Cortex Medical, Leipzig, Germany) and the facemask. Study participants were not allowed to exercise for 48 h before testing, and were recommended a normal, balanced diet.

The equipment was calibrated before each test with known O2 and CO2 concentrations, while the participants were adapting to the testing environment. In the beginning of the test, we measured heart rate (HR, bpm), the systolic (SBP, mmHg) and diastolic blood pressures (DBP, mmHg) by using General Electric HEALTCARE B20 device (General Electric, Boston, MA, USA). From the supine position, the energy expenditure was measured as kilocalories (kcal) per minute/hours/day. The respiratory coefficient (RQ) was measured next to oxygen consumption (VO2, L/min) and carbon dioxide production (VCO2, L/min). By using these parameters, we appreciated the carbohydrate metabolism (CHO, grams per day, %) next to the fat metabolism (Fat, grams per day, %). Additional information was provided through the standard protocol and the MetaSoft 3 use: body mass index (BMI) and resting energy requirement (kcal/day) which was calculated automatically by applying the Harris Benedict equation [27].