This review article is concerned with human energy metabolism, in particular describing individual com- ponents and factors that influence energy requirements. The article goes on to discuss energy balance of the organism and the influence that changes in energy intake háve on energy expenditure. One section is dedicated to the most commonly ušed equations for calculating energy expenditure and nut- ritional needs. Finally, an attempt is made to describe the most widely ušed methods for measuring energy expenditure - outlining the advantages, as well as limitations and technical problems, with using each of them.

        Key words: energy expenditure, energy metabolism, indirect calorimetry, energy expenditure assessment.