BACKGROUND: The doubly labelled water (DLW) method is an isotope-based technique that quantifies total energy expenditure (TEE) over periods of 1-3 weeks from the differential elimination of stable isotopes of oxygen and hydrogen. The method was invented in the 1950s, but limited ability to measure low isotope enrichments combined with the high cost of isotopes meant it only became feasible to use in humans in the 1980s. It is still relatively expensive to use, and alone small samples are unable to tackle some of the important questions surrounding energy balance such as how have expenditures changed over time and how do expenditures differ with age, between sexes and in different environments?
SUMMARY: By combining information across studies, answers to such questions may be possible. The International Atomic Energy Agency (IAEA) DLW database was established to pool DLW data across multiple studies. It was initiated by the main labs currently using the method and is hosted by the IAEA. At present, the database contains 6,621 measures of TEE by DLW from individuals in 23 countries, along with various additional data on the study participants. Key Messages: The IAEA DLW database is a key resource enabling future studies of energy demands.
Bibliographical noteFunding Sources
The database is generously supported by the IAEA and by the companies Taiyo Nippon Sanso, SERCON and ISOTEC. We are grateful to these companies for their support and especially to Takashi Oono for his tremendous efforts at fund raising on our be half. The authors also gratefully acknowledge funding from the US National Science Foundation (BCS-1824466) awarded to Herman Pontzer. The funders played no role in the content of this manuscript. Open access provided with a grant from the International Atomic Energy Agency.
All authors contributed to the drafting and editing of the manuscript and to construction of the IAEA DLW database.
- Energy expenditure
- Doubly labelled water
- Food requirements