Estimating free-living human energy expenditure: Practical aspects of the doubly labeled water method and its applications

Abstract

The accuracy and noninvasive nature of the doubly labeled water (DLW) method makes it ideal for the study of human energy metabolism in free-living conditions. However, the DLW method is not always practical in many developing and Asian countries because of the high costs of isotopes and equipment for isotope analysis as well as the expertise required for analysis. This review provides information about the theoretical background and practical aspects of the DLW method, including optimal dose, basic protocols of two- and multiple-point approaches, experimental procedures, and isotopic analysis. We also introduce applications of DLW data, such as determining the equations of estimated energy requirement and validation studies of energy intake.

Descripción de los instrumentos de medida de la movilidad en personas mayores de 65 años: revisión sistemática

“…El total de artículos seleccionados fueron 34, de los que 23 correspondieron exclusivamente a cuestionarios4 ,8,10,12-14,25,31-34,36-40,42-48 , 4 a acelerómetros 11,[21][22][23] , 3 a las medidas objetivas de la movilidad [28][29][30] , 2 artículos eran sobre podómetros 19,20 y 2 para DLW 18,26 . Y 6 hacían referencia al análisis combinado de diferentes instrumentos 16,17,24,27,35,41 .…”

“…De los 34 estudios, 19 fueron estudios transversales 40,42,44,46-48, 5 longitudinales 29,32,34,38,45 y 10 eran revisiones bibliográficas 12,13,[18][19][20][21][22][23]28,43 . Todos ellos incluyeron información relativa a la fiabilidad y/o validez del instrumento de medida utilizado.…”

“…En la tabla 1 se refleja una síntesis de las ventajas e inconvenientes de los instrumentos que fueron seleccionados en este artículo. Los 2 artículos 18,26 que abordaron el agua doblemente marcada (DLW) coincidieron en señalar que este método determinó de forma exacta la energía gastada por los individuos a partir de la velocidad de producción de dióxido de carbono (CO 2 ) que fue hallada mediante 2 isótopos estables: deuterio (2H) y oxígeno-18 (18O). La principal ventaja fue que el DLW fue el método más preciso para medir la movilidad, siendo el estándar de oro para el análisis de la validez de los instrumentos de movilidad.…”

Measures of Total Energy Expenditure and Its Components Using the Doubly Labeled Water Method in Rehabilitating Burn Children

“…Once a dose of water containing the combined stable isotopes, hence doubly labeled water (D 2 O 18 ), is eliminated from the body, the H 2 O 18 is eliminated as both CO 2 and H 2 O, while the D 2 O is eliminated only as H 2 O. Thus, the difference between these elimination rates is a measure of CO 2 flux, which can be related to energy expenditure using standard calorimetric equations 18 , 23 . ‐ 25 While this method has been used in critically ill burn children, 19 the DLW method is best suited for measuring TEE in free‐living subjects 23 , 25 .…”

“…“Snapshot” measurements most likely representing REE do not capture variations in activity and physiologic state that take place throughout the day and over the course of injury 15 , 16 . The doubly labeled water (DLW) method using stable isotopes of hydrogen and oxygen is safe, is nonrestrictive, and has been extensively validated for determining total energy expenditure (TEE) in free‐living adults and children 17 , 18 . The DLW method has been used by Goran et al 19 in acute burned children, providing information on the 24‐hour needs of patients during their acute phase of care.…”