Validation studies have shown that the appropriate use
of the minute-by-minute heart-rate method for estimating energy expenditure
provides a suitable alternative when high accuracy in individual subjects is not
required. It can be used under field conditions and gives excellent measurements
of average energy expenditure in small groups of subjects. It is also useful for
obtaining the activity pattern of individuals or groups.
Interest in the measurement of energy expenditure (EE) in
free-living subjects is evident from the articles presented in this volume.
There is widespread attraction to the application of the doubly-labelled water
(2H218O) method because of its accuracy in
individual subjects (WESTERTERP et al., 1988). However, it has two
drawbacks that limit its use in many settings and in some kinds of research
project. The expectations that its cost (~300 US$/subject; SCHOELLER, 1988)
would be reduced have not been realized. In addition, the highly technical
nature of mass-spectrometric analysis requires equipment and training which are
formidable. The second drawback is that it gives an average of the energy
expenditure over the period of measurement, i.e., it cannot provide the pattern
of energy expenditure.
The purpose of this article is to describe an alternative to the
2H218O method which may prove useful in many