Measurement of energy expenditure.

Although investigators have been engaged in the study of human energy metabolism for over 100 years, there remain unanswered questions regarding the role that energy expenditure plays in human health and disease. A critical examination of available methods for measurement of the various components of daily energy expenditure is presented. Using a combination of the techniques available today, each component can be reliably studied, and the role that each of these plays in the human health can be examined. Several examples of the application of energy expenditure methods are presented. Finally, data are presented describing current knowledge regarding the relation between energy metabolism and cancer, including cancer risk, response to cancer, and in cancer survivors.