Contributions of the doubly labeled water method to studies of energy balance in the Third World

Of >250 studies on energy metabolism using the doubly labeled water (DLW) technique, approximately 12 full papers describe work performed in the Third World. Unfortunately, the term "Third World" is imprecise and the focuses of individual studies were too varied to allow much comparison among the data. There is a need to develop a more uniform approach. Useful investigations will allow comparisons of energy metabolism to be made in a consistent way across a variety of socioeconomic groups within the same country, and between the Third World and the developed world, with a commitment to the long term. In this way, the DLW method, if combined with other measurements of activity, energy intake, and body composition, will provide useful information on energy requirements and the consequences of inadequate or excessive energy intakes for the individual. Such investigations should be done, with standard protocols where possible, not just for the DLW method but also for those methods with which DLW should be integrated. Only if these suggestions are followed will real "value for money" be obtained from DLW studies in the Third World or elsewhere. In the context of these criteria, studies in the Third World using the DLW method have been only partly successful.