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Measurement of total body water using 2H dilution: impact of different calculations for determining body fat

Published online by Cambridge University Press:  09 March 2007

J. LaForgia*
Affiliation:
School of Pharmaceutical, Molecular and Biomedical Sciences, University of South Australia, GPO Box 2471, Adelaide, South Australia 5001, Australia
R. T. Withers
Affiliation:
Exercise Physiology Laboratory, School of Education, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia
*
*Corresponding author: Dr J. LaForgia, fax +618 8302 2389, email joe.laforgia@unisa.edu.au
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Abstract

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This study estimated total body water (TBW) in four groups (twelve per group; sedentary and highly trained men and women) at the time of 2H dosing (T0) and after a 3·5 h equilibration period (Teq). Standard TBW calculations were employed at T0 (no correction for disproportionate urinary tracer loss) and Teq (correction for urinary tracer loss only), plus those calculations that corrected for a disproportionate urinary tracer loss and insensible tracer loss respectively. The measurement of body density enabled the four TBW estimates to be compared for the determination of three-compartment % body fat (BF). The very small difference between the standard and corrected T0 TBW data was not significant (P=0·914) and no Group×TBW interaction was identified (P=0·125). These results reflect the closeness of the 2H concentration in the urine produced during the equilibration period and the Teq saliva samples. The associated mean % BF values were essentially identical. Although correcting for insensible 2H losses in addition to urinary losses at Teq produced a statistically significant (P<0·001) lower mean TBW (about 200 g) than the standard calculation, this translated to a small difference in % BF (0·3). The larger difference (about 500 g, P<0·001) between the two (T0, Teq) corrected TBW calculations was also associated with a small body composition difference (0·1 % BF), which was less than the propagated error (0·3 % BF) for the three-compartment body composition model. Corrections to the standard calculations of TBW at T0 and Teq for a protocol employing a brief equilibration period (3·5 h) were therefore of marginal use for improving the accuracy of % BF estimates. The TBW difference over time (T0v. Teq) also had little impact on % BF values.

Type
Research Article
Copyright
Copyright © The Nutrition Society 2002

References

Brozek, J, Grande, F, Anderson, JT & Keys, A (1963) Densitometric analysis of body composition: revision of some quantitative assumptions. Annals of the New York Academy of Sciences 110, 113140.CrossRefGoogle ScholarPubMed
Fidanza, F, Keys, A & Anderson, JT (1953) Density of body fat in man and other mammals. Journal of Applied Physiology 6, 252256.Google Scholar
Lentner, C (1981) Geigy Scientific Tables: Vol. 1. Units of Measurement, Body Fluids, Composition of the Body, Nutrition. Table 50. Basle: Ciba Geigy Ltd.Google Scholar
Schoeller, DA (1996) Hydrometry. In Human Body Composition, pp. 2543 [Roche, AF, Heymsfield, SB and Lohman, TG, editors]. Champaign, IL: Human Kinetics.Google Scholar
Schoeller, DA, Kushner, RF, Taylor, P, Dietz, WH & Bandini, L (1985) Measurement of total body water: isotope dilution techniques. In Sixth Ross Conference on Medical Research: Body Composition Assessments in Youth and Adults, pp. 2429Columbus, OH: Ross Laboratories.Google Scholar
Schoeller, DA, Ravussin, E, Schutz, Y, Acheson, KJ, Baertschi, P & Jequier, E (1986) Energy expenditure by doubly labeled water: validation in humans and proposed calculation. American Journal of Physiology 250, R823R830.Google ScholarPubMed
Siri, WE (1956) The gross composition of the body. In Advances in Biological and Medical Physics, pp. 239280 [Lawrence, JH and Tobias, CA, editors]. New York: Academic Press.Google Scholar
Withers, RT, LaForgia, J & Heymsfield, SB (1999) Critical appraisal of the estimation of body composition via two-, three-, and four-compartment models. American Journal of Human Biology 11, 175185.Google Scholar
Withers, RT, LaForgia, J, Heymsfield, SB, Wang, Z-M, & Pillans, RK (1996) Two, three and four-compartment chemical models of body composition analysis. In Anthropometrica, pp. 199231 [Norton, KI and Olds, TS, editors]. Sydney: University of New South Wales Press.Google Scholar
Wong, WW, Cochran, WJ, Klish, WJ, Smith, EO, Lee, LS & Klein, PD (1988) In vivo isotope-fractionation factors and the measurement of deuterium- and oxygen-18-dilution spaces from plasma, urine, saliva, respiratory water vapour, and carbon dioxide. American Journal of Clinical Nutrition 47, 16.CrossRefGoogle Scholar