doubly labeled water


doub·ly la·bel·ed wa·ter

(dŭb'lē lā'bĕld waw'tĕr) Noncalorimetric technique for measuring energy expenditure in free-living subjects using an oral dose of water containingstable nonradioactive isotopes, 2H and 18O. Derived CO2 production is used to calculate energy expenditure using indirect calorimetry formulas.