Validation of the Quark RMR Calorimeter (Cosmed) Versus Deltatrac II (GE Health Care Clinical Systems) for Measuring Energy Expenditure at Rest and in Dynamic Phase After a Meal in Adult Healthy and Obese Volunteers

Clinically, energy expenditure is usually estimated using predictive equations, such as the Harris-Benedict equation, which consider the patient's weight, height, age and sex to determine energy needs. However these have been shown to be unsystematically incorrect and may vary by 70-140% when compared with indirect and direct calorimetry measurements.

That is why the most popular method of measurement of energy expenditure in research is via indirect calorimetry using a metabolic cart. Indirect calorimetry is the measurement of the volume of oxygen consumption and carbon dioxide production.

Actually, there are few numbers of indirect calorimeters available commercialy. The Deltatrac II metabolic cart was the gold standard. It has been extensively used in clinical research both for resting metabolic rate and substrate oxidation measurement during postprandial or an insulin clamp. The Quark RMR is also a metabolic cart too which was launched on the market to compete with the others calorimeters measuring resting metabolic rate.

As the Quark RMR and Deltatrac II use the same measure device (paramagnetic analyser for oxygen detection, infrared absorption for carbon dioxide detection) with the same sensitivity and time response according to constructor's data, we want to compare these two calorimeters for the measurement of energy expenditure and substrate oxidation at rest and during a meal in standardized conditions.