Doubly Labeled Water Energy Expenditure

35+ Years exclusively in stable isotope tracer studies

Experimental protocol designs and results delivered weeks faster than CROs

GLP-compliant, CLIA-certified, 21 CFR Part 11 validated

Consultative approach, with over 1,000+ studies guided from design to submission

Method Overview

Why Use the Doubly Labeled Water Method?

The DLW method is the gold standard of indirect calorimetry, validated extensively in both animals and humans.

Safe & non-invasive - Requires only plasma, urine, or saliva samples.
Non-restrictive - Ideal for patients, children, and even field studies.
Trusted worldwide - Proven in thousands of studies across clinical and research settings.

With Metabolic Solutions, you get data regulators trust and timelines researchers need.

Baseline sample collection

Plasma, saliva, or urine is obtained to determine pre-dose isotope levels.

Tracer dosing

Subjects receive a single oral bolus of heavy water (²H₂¹⁸O).

Adults: ~0.15 g H₂¹⁸O/kg body weight and 0.06 g ²H₂O/kg.
Children and neonates: Higher doses per kg due to faster water turnover rates.

Follow-up sampling

Additional body fluid samples collected 1–2 weeks later.

Isotope analysis

We measure deuterium and oxygen-18 enrichments with high sensitivity from just 15–25 µl of sample.

Energy expenditure calculation

Output is total daily energy expenditure, derived from isotope elimination rates.

Application	Subject Type	Reference
Musculoskeletal Health	Middle-age women and men	Total daily energy expenditure: OPEN Study	Download
Weight loss studies	Adults	Long-term effects of energy-restricted diets	Download
Total daily energy expenditure	Children	Energy expenditure predicts changes in body fat in children	Download
Comparisons of food frequency questionnaires	Adults	Accuracy of dietary assessment methods	Download
Total daily energy expenditure	Small animals	DLW studies in mice	Download
Field metabolic studies	Animals	Field metabolic rate and body size	Download

They’ve been very consistent… the sample analysis and data has always been timely and high quality.

There are academic labs that do it as well, but they’re much harder to engage and contract with.

I think they’re extremely organized and very on top of sample management. All the interactions that I’ve had with them have been great.

Yes. DLW uses non-radioactive stable isotopes (²H and ¹⁸O) that are completely safe, even for children, neonates, and animal studies.

The protocol generally requires baseline sampling, a single oral tracer dose, and follow-up samples collected 1–2 weeks later.

Absolutely. We provide consultation on tracer dosing, sampling protocols, and regulatory considerations, ensuring data that meets GLP and FDA/EMA standards.

Metabolic Solutions, LLC.
460 Amherst St., Nashua,
NH 03063, USA

Phone: (603) 598-6960

Fax: (603) 598-6973

info@metsol.com

Hours of Operation
Monday – Friday
7:30 am – 6:00 pm EST

Metabolic Solutions offers a broad spectrum of assays utilizing stable isotopes such as carbon-13 (¹³C), nitrogen-15 (¹⁵N), deuterium (²H), and oxygen-18 (¹⁸O).

We have developed and validated non-invasive breath tests that assess sugar intolerances and gastrointestinal health.

Stable Isotope Assays for Energy Expenditure Measurement with the Doubly Labeled Water (DLW) Protocol

What Sets Us Apart in Metabolic Biomarker Analysis

Why Use the Doubly Labeled Water Method?

How the Doubly Labeled Water Method Works

How Researchers Use the Doubly Labeled Water Method

Want to Learn More?

All Analyses Are Performed In Our Certified Laboratory Environment

Trusted by Leaders in Metabolic Research

Frequently Asked Questions

Is the DLW method safe for humans and animals?

What is the typical study duration?

Do you assist with study design and regulatory requirements?

Talk to our isotope experts today about designing your DLW study and getting results regulators trust

Contact us

Research Services

GI Breath Tests

About Metabolic Solutions

Metabolic Solutions offers a broad spectrum of assays utilizing stable isotopes such as carbon-13 (13C), nitrogen-15 (15N), deuterium (2H), and oxygen-18 (18O).

We have developed and validated non-invasive breath tests that assess sugar intolerances and gastrointestinal health.

Stable Isotope Assays for Energy Expenditure Measurement with the Doubly Labeled Water (DLW) Protocol

What Sets Us Apart in Metabolic Biomarker Analysis

Why Use the Doubly Labeled Water Method?

How the Doubly Labeled Water Method Works

How Researchers Use the Doubly Labeled Water Method

Want to Learn More?

All Analyses Are Performed In Our Certified Laboratory Environment

Trusted by Leaders in Metabolic Research

Frequently Asked Questions

Is the DLW method safe for humans and animals?

What is the typical study duration?

Do you assist with study design and regulatory requirements?

Talk to our isotope experts today about designing your DLW study and getting results regulators trust

Contact us

Research Services

GI Breath Tests

About Metabolic Solutions

Metabolic Solutions offers a broad spectrum of assays utilizing stable isotopes such as carbon-13 (¹³C), nitrogen-15 (¹⁵N), deuterium (²H), and oxygen-18 (¹⁸O).