Abstract:The process of energy expenditure in patients with sepsis is complex. In the acute phase, due to the catabolic state, endogenous energy production increases, which is almost sufficient to meet energy requirements, and exogenous nutrition cannot eliminate this endogenous energy production.Therefore, nutritional support should be based on low calories during this phase. Thereafter, energy expenditure increases and remains elevated for 3 weeks after ICU admission, when endogenous energy production decreases and exogenous nutritional support is essential. Indirect calorimetry is the gold standard for bedside assessment of energy expenditure. Nutrition guidelines recommend the use of indirect calorimetry to guide nutritional therapy in critically ill patients, in order to prevent the adverse effects of malnutrition and overnutrition. Therefore, the use of indirect calorimetry to help patients with sepsis develop personalized nutritional support regimens can improve the patients nutritional status and thus their long-term prognosis.