Work

Evaluation of the effects of a new standard equation for doubly labeled water studies

Year: 2026

Type: article

Abstract: Accurate measurement of energy expenditure is critical for metabolic research and public health. Doubly labeled water (DLW) is the gold standard for assessing free-living energy expenditure, yet inconsistencies in equations impede comparability across studies. This analysis evaluates a newly proposed standardized equation of energy expenditure from the DLW method against commonly employed historical equations. Using validation data from whole-room indirect calorimetry, we demonstrate that the new equation offers improved accuracy. Further, analysis of a large historical dataset and mathematical modeling revealed a systematic bias of ∼1.6%, indicative of an underestimation of energy expenditure estimates with the new equation compared to previous equations. Application of a newly developed correction factor mitigated this bias, allowing for closer alignment between equations. These findings support adoption of the new standard equation and offer a corrective approach for harmonizing data, thereby facilitating methodological consistency in DLW studies and allowing for the preservation of the utility of historical datasets.

Source: Cell Reports Methods

DOI: 10.1016/j.crmeth.2025.101274