Stable isotopes in nutritional science and the study of energy metabolism

Abstract

The presence in nature of stable isotopic forms of almost all the elements in organic molecules, and of many minerals of nutritional interest, offers enormous possibilities for their application in human nutrition research. This review summarises the range of applications and discusses the reasons why some have proved more productive than others. Discoveries stemming from the use of the doubly-labelled water (2H218O) method for assessing energy expenditure are considered in depth in order to illustrate the great potential of isotope techniques. An analysis of the reasons for this success concludes that there is a need for the development of world- wide consensus on standardised procedures for stable isotope methods. The development of such protocols, together with strong partnerships between mass spectrometrists and biologists, will unlock the great potential of other stable isotope methods.