A literature search over the past decade reveals very few papers
containing new data on energy expenditure during infancy. This is largely due to
the difficulty of performing the necessary measurements in any circumstances
other than when children are asleep. Torun discusses the problems in detail
elsewhere in this volume and points out the limitations of attempting to predict
total energy expenditure of children by the factorial method (TORUN, 1990).
Similarly, Spurr describes the use of heart-rate monitoring and its limitations
in very young children for whom calibrations cannot be obtained (SPURR, 1990).
The development of the doubly-labelled water method for use in man
has removed these limitations and promises to revolutionise our concepts of
energy metabolism and requirements in these age groups. This paper provides a
description of the new method and a review of the results obtained so