Doubly Labeled Water Isotope Grant Program
The Doubly Labeled Water (DLW) method is the gold-standard for measuring total daily energy expenditure (kcal/day or MJ/day) during normal daily life, outside of a laboratory setting. Since its development for use in human research in the 1980’s, the DLW method has revolutionized our understanding of metabolism and its connections to health and disease, body size and obesity, growth and aging, reproduction, and lifestyle.
The cost of isotopically enriched water has been a major obstacle for DLW research, particularly for populations and settings outside the focus of biomedical research and funding. The Doubly Labeled Water Isotope Grant program aims to address these challenges and expand the use of the DLW method by providing isotopically-enriched water for DLW research.
This program will provide water enriched to ~6% 2H2O and ~10% H218O, the level of enrichment typically used in human DLW studies, to researchers. The grant program only provides isotopically enriched water. All other costs for data collection and analysis, including isotopic analysis of samples, must be supported by the applicants. Only human studies are eligible for this program (i.e., studies in rodents or other species are not eligible).
APPLY to the Doubly Labeled Water Isotope Grant program
Information for Applicants
Important Dates
January 9, 2026: Deadline for applications
March 2026: Awards announced
March – April 2026: Enriched water shipped to awardees
Program Requirements
- Data Sharing Grant recipients must agree to share their data (DLW measurements including k and N values, anthropometric data, related health metrics, accelerometry, etc. for each DLW measurement) to the DLW Database.
- Funding Grant recipients must have funding in place to support shipment of the water to their lab, and for data collection and analysis. The DLW Isotope Grant Program only provides the isotopically enriched water.
- Permits Grant recipients must have IRB and other research permissions. Applicants may be required to provide documentation of research permissions before receiving awards.
- DLW Lab Letter of Support Applicants must provide a letter of support from a recognized DLW laboratory stating that they agree to analyze the samples generated by the project. The lab must also agree to share isotopic data (k and N values) with the DLW Database.
Who can apply for this program?
Professors, postdocs, research scientists, and PhD students at universities and other non-profit research institutions are eligible to apply. Applicants outside the U.S. are eligible, but must provide a clear plan for shipping and receiving the enriched water, including coverage for the cost of shipping the isotope-enriched water to your lab.
What projects are eligible? What projects will be prioritized?
Only human studies are eligible for this program. Studies addressing under-studied populations, and those that address novel questions in human energetics, life history, health, or ecology will be prioritized. Projects with populations who have not been studied previously using DLW, or who have limited access to traditional avenues for biomedical funding, will also be prioritized. Applications should clearly articulate how the study they propose addresses gaps in current DLW research and/or populations that have not been investigated using DLW.
How much does DLW isotope analysis cost?
Analysis costs are not supported by this program, and they vary by lab. We encourage applicants to contact DLW labs to discuss costs.
What if I don’t have funding for data collection and analysis costs?
A limited number of provisional awards will be granted each cycle for projects that have not yet secured funding for data collection and sample analysis. Provisional awards will provide a letter of support from the program that guarantees the provision of enriched water for up to 18 months post-award. Enriched water will be sent to the researcher only when they have secured funding for the project. If the researcher is unable to secure funding within 18-months of a provisional award, they will need to apply again via the normal process.
How much enriched water can I request, and how do I determine the amount I need?
The amount of enriched water available for these grants is limited. We anticipate being able to support projects with ~20 to ~60 participants. Applicants with larger projects may wish to contact Herman Pontzer herman.pontzer@duke.edu to discuss feasibility. Applications should request the minimum amount of enriched water needed to achieve the project aims, and should clearly describe the rationale for the sample size, number of measurements, and total amount of enriched water requested. You can refer to the dosing table here, which provides the typical dose size for humans based on bodyweight. You can also discuss dosing volumes with your DLW analysis lab.
If you have questions about the Doubly Labeled Water Isotope Grant program, email Herman Pontzer, herman.pontzer@duke.edu
