Table 1.

Key articles in development of the doubly labelled water method for the measurement of energy expenditure

1949	Discovery that the oxygen in respiratory carbon dioxide is in isotopic equilibrium with the oxygen in body water (Lifson et al. 1949)
1955	Description of the measurement of carbon dioxide production from isotopic analysis of body water (Lifson and McClintock 1955)
1964	Doubly labelled water assessment of the energy cost of flying in pigeons (LeFebvre 1964)
1966	Review paper on a model for doubly labelled water assessment of energy expenditure in free-ranging animals (Lifson and McClintock 1966)
1982	Validation of the doubly labelled water method for the measurement of energy expenditure in humans (Schoeller and Van Santen 1982)
1988	Workshop on standardization of the doubly labelled water method for the measurement of energy expenditure in humans (Prentice 1990)
1994	Symposium on advances in the doubly labelled water technique (Speakman and Roberts 1995)