Use of Indirect Calorimetry in Obesity

"Indirect calorimetry will be performed by using an open-circuit calorimeter (Sensor Medics, Italy). Indirect calorimetry is the reference method for energy expenditure determination. A canopy hood covered the patient's head and expired air is extracted by a pump to be analyzed by metabolic cart sensors; flow rate is directly measured with a digital turbine flowmeter. After an overnight fast, patients will asked to lay supine in complete physical rest, not sleeping or talking for approximately 20-25 minutes, at a room temperature ranged between 22 and 24°C. The mean REE for each participant considers the last 15-20 minutes of measurements corresponding to steady state.~Software of calorimeter will be set for minute-by-minute reading report of VO2 (Oxygen flow) and VCO2 (Carbon dioxide flow) measurement.~Parameters obtained by Indirect Calorimetry will be the Resting Energy Expenditure and the Respiratory Quotient (RQ)"