Children’s Nutrition Research Center Staff Publications
Publication Date
2-16-2021
Journal
Cell Reports Medicine
DOI
10.1016/j.xcrm.2021.100203
PMID
33665639
PMCID
PMC7897799
PubMedCentral® Posted Date
2-16-2021
PubMedCentral® Full Text Version
Post-print
Published Open-Access
yes
Keywords
Body Composition, Calorimetry, Indirect, Deuterium, Energy Metabolism, Humans, Oxygen Isotopes, Water, total energy expenditure, free-living, validation, doubly labeled water
Abstract
The doubly labeled water (DLW) method measures total energy expenditure (TEE) in free-living subjects. Several equations are used to convert isotopic data into TEE. Using the International Atomic Energy Agency (IAEA) DLW database (5,756 measurements of adults and children), we show considerable variability is introduced by different equations. The estimated rCO2 is sensitive to the dilution space ratio (DSR) of the two isotopes. Based on performance in validation studies, we propose a new equation based on a new estimate of the mean DSR. The DSR is lower at low body masses (<10 kg). Using data for 1,021 babies and infants, we show that the DSR varies non-linearly with body mass between 0 and 10 kg. Using this relationship to predict DSR from weight provides an equation for rCO2 over this size range that agrees well with indirect calorimetry (average difference 0.64%; SD = 12.2%). We propose adoption of these equations in future studies.
Graphical Abstract
Included in
Biochemical Phenomena, Metabolism, and Nutrition Commons, Dietetics and Clinical Nutrition Commons, Endocrinology, Diabetes, and Metabolism Commons, Nutrition Commons