Energy equivalents of CO2 and their importance in assessing energy expenditure when using tracer techniques
Elia, M.
American Journal of Physiology 260(1 Pt 1): E75-E88
1991
ISSN/ISBN: 0002-9513 PMID: 1899005 Document Number: 374823
Energy equivalents for CO2 (EeqCO2) of 63 randomly selected British people, whose dietary intake was assessed over 7 days, varied by less than 10% (mean value 23.8 kJ/litre). However, EeqCO2 for different populations varied by more than 10%. For 60 commercially available artificial enteral feeds EeqCO2 values varied by about 20% (mean value 23.4 kJ/litre). Alcohol increased the variability of EeqCo2, and persons with alcohol problems had values around 26.7 kJ/litre. Variations in the nitrogenous end products of metabolism, and nutrient/energy imbalances, may have major effects on EeqCO2. It is concluded that the calculation of energy expenditure from CO2 production should not employ a universal value for EeqCO2. The value should take into account the physiological and clinical state under investigation.