Residual volume as a tool in body fat prediction.
Possible methods of estimating residual volume for the prediction of body fat have been compared in young and healthy adults, with particular reference to the potential of a rapid helium equilibration method. In the first experiment, 5 women and 5 men performed nitrogen elimination, oxygen dilution and helium equilibration tests; scores for the helium test were higher than for the other two methods, but lay between the predictions made by Bass in 1964 and by Wilmore in 1969 and the values predicted by the equation of Goldman and Becklake in 1959. However, estimates of body density and body fat, based on residual volumes obtained from the prediction equations, did not differ significantly from those obtained directly by helium equilibration. A second experiment compared the helium and the oxygen techniques in 18 men and 18 women, with similar results. A final experiment compared the simple helium equilibration procedure with vital capacity and anthropometric predictions also suited to large scale determinations of body composition. It is concluded that the rapid helium equilibration procedure provides a fast and convenient procedure for the residual volume component of a body fat estimation. However, further study of the adequacy of equilibration is needed in older subjects and in patients with chronic chest disease.