A prospective randomised study comparing oral 13C-bicarbonate tracer technique versus indirect calorimetry for measurement of energy expenditure in adults

Abstract

Background and Aims-Accurate assessment of energy expenditure (EE) is important in guiding nutritional therapy but current methods are unsatisfactory. This study compared the oral 13 C-bicarbonate tracer (BT) technique using the IRIS® system (Wagner, Germany) against indirect calorimetry (IC, ventilated-hood) to measure CO 2 output (VCO 2 ) and thus estimate EE.