1.1. Energy expenditure of free-living populations

There is general agreement that more information is needed on total energy expenditure of free-living individuals, especially hard-working ones, including children, in developing countries.

The doubly-labelled water method can provide this information over extended periods of time. Unfortunately three problems in connection with this method have appeared: (1) some results do not seem biologically plausible; indeed, some astonishing figures were presented at this meeting, (2) there is a world-wide shortage of ¹⁸O, and (3) several mass spectrometers have produced unreliable data. More small-scale validation studies are therefore needed before large-scale studies can be justified.