Every need is perfectly met if you do not measure it

In the study on critically ill patients by De Waele et al.1, published in this issue of Minerva Anestesiologica, total energy expenditure (TEE) estimated by indirect calorimetry (IC) is compared to that calculated with Harris-Benedict and other predictive equations. Energy is the basis of life; from the cell physiologist’s point of view, TEE is equal to the sum of membrane transport, protein turn-over and metabolic cycles. For the clinical physiologist, TEE is represented by basal metabolic rate (BMR, 60-75% of TEE), diet induced thermogenesis (DIT, 5-15%) and physical activity (PA, 15-30%).