DOUBLY LABELED WATER MEASUREMENT OF TOTAL-ENERGY EXPENDITURE

The doubly labelled water method uses the principles of indirect calor imetry to measure total energy expenditure from the turnover rates of two stable isotopes : deuterium and oxygen 18. Labelling total body wa ter also provides estimates of body composition and measurements of wa ter outflow rates. Although the principle of the method was determined in the 1950s, it was only applied to humans in the 1980s. Some 15 yea rs later, it is time for an objective appraisal of the method. This re view first describes the principle and practice of the doubly labelled water method. The original concept described by Lifson and MacClintoc k is then discussed, and proposals are made to adapt the method to phy siological and pathophysiological situations.