By introducing this system, energy expenditure of an individual can be calculated and thereby may overcome shortcomings of prediction equations at the individual level. The breath-by-breath technique of the Cortex MetaLyzer® 3B measures VO2 and VCO2 for assessing energy expenditure [27]. Limited studies were found who determined the reliability of the Cortex MetaLyzer® 3B. No studies regarding its accuracy were found. A previous study at the Wilhelmina Children's Hospital indicated that the Cortex MetaLyzer® 3B is reproducible for measuring REE in a small paediatric population [28]. However, a recommendation was made to further investigate the validity of the Cortex MetaLyzer® 3B. According to Meyer et al [29], it seems to be a reliable system for testing energy expenditure in a research setting. Nonetheless, they emphasise that fluctuations of individual measurements in the breath-by-breath mode of the Cortex MetaLyzer® 3B may occur [29]. Furthermore, these studies were only performed in exercise testing conditions and no resting conditions were taken into
By introducing this system, energy expenditure of an individual can be calculated and thereby may overcome shortcomings of prediction equations at the individual level. The breath-by-breath technique of the Cortex MetaLyzer® 3B measures VO2 and VCO2 for assessing energy expenditure [27]. Limited studies were found who determined the reliability of the Cortex MetaLyzer® 3B. No studies regarding its accuracy were found. A previous study at the Wilhelmina Children's Hospital indicated that the Cortex MetaLyzer® 3B is reproducible for measuring REE in a small paediatric population [28]. However, a recommendation was made to further investigate the validity of the Cortex MetaLyzer® 3B. According to Meyer et al [29], it seems to be a reliable system for testing energy expenditure in a research setting. Nonetheless, they emphasise that fluctuations of individual measurements in the breath-by-breath mode of the Cortex MetaLyzer® 3B may occur [29]. Furthermore, these studies were only performed in exercise testing conditions and no resting conditions were taken into