The Doubly Labeled Water Method Produces Highly Reproducible Longitudinal Results in Nutrition Studies

Abstract

The doubly labeled water (DLW) method is considered the reference method for the measurement of energy expenditure under free-living conditions. However, the reproducibility of the DLW method in longitudinal studies is not well documented. This study was designed to evaluate the longitudinal reproducibility of the DLW method using 2 protocols developed and implemented in a multicenter clinical trial-the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE). To document the longitudinal reproducibility of the DLW method, 2 protocols, 1 based on repeated analysis of dose dilutions over the course of the clinical trial (dose-dilution protocol) and 1 based on repeated but blinded analysis of randomly selected DLW studies (test-retest protocol), were carried out. The dose-dilution protocol showed that the theoretical fractional turnover rates for (2)H and (18)O and the difference between the 2 fractional turnover rates were reproducible to within 1% and 5%, respectively, over 4.5 y. The Bland-Altman pair-wise comparisons of the results generated from 50 test-retest DLW studies showed that the fractional turnover rates and isotope dilution spaces for (2)H and (18)O, and total energy expenditure, were highly reproducible over 2.4 y. Our results show that the DLW method is reproducible in longitudinal studies and confirm the validity of this method to measure energy expenditure, define energy intake prescriptions, and monitor adherence and body composition changes over the period of 2.5-4.4 y. The 2 protocols can be adopted by other laboratories to document the longitudinal reproducibility of their measurements to ensure the long-term outcomes of interest are meaningful biologically. This trial was registered at clinicaltrials.gov as NCT00427193.

Meal timing during alternate day fasting: Impact on body weight and cardiovascular disease risk in obese adults

“…The reason for this is unclear as all groups lost the same amount of lean mass, and lean mass is a key predictor of RMR (22). Whether or not these RMR findings can be reproduced using a more robust technique for measuring energy expenditure, such as doubly labeled water (23), is well warranted.…”

Energy Intake and Energy Expenditure for Determining Excess Weight Gain in Pregnant Women

“…Mifflin St. Jeor, Harris-Benedict) estimate resting metabolic rate or basal metabolic rate for the population in general and then a trained individual selects activity and illness factors to determine daily energy requirements (21, 22). Luckily in this study, we were able to estimate energy requirement in trimester 2 using doubly labeled water which is the most accurate way to estimate total energy expenditure in free living individuals (23, 24). Estimated energy intake in trimester 3 is the doubly labeled water total energy expenditure measured in trimester 2 plus the energy stored as fat and muscle mass specific to each patients weight gain.…”

“…Saliva samples were analyzed for hydrogen and oxygen isotope ratio measurements by gas-isotope-ratio mass spectrometry (16). Turnover rates of 2 H and 18 O were converted to total energy expenditure using the Weir equation (15) and a food quotient of 0.86, the value traditionally used based on the standard American diet (23). Adaptive changes in total energy expenditure at the third trimester were determined as the difference between the measured total energy expenditure and the predicted total energy expenditure.…”

Portion‐controlled meals provide increases in diet quality during weight loss and maintenance

“…Secondly, there is no comparison group to see if the same changes in HEI-2010 scores are obtained using traditional, reduced-energy meal plan diets. Finally, dietary intake was collected by self-reported diet records, which can be biased by social desirability or social approval 28 and have been shown to underestimate EI when compared with energy expenditure assessed by doubly labeled water 29–33 .…”