Highlight
– Persistently elevated normalized resting energy expenditure (nREE) measured by indirect calorimetry was independently associated with greater loss of skeletal muscle cross-sectional area (L3 CSA) in critically ill adults.
– Patients classified as hypermetabolic had faster muscle wasting and higher likelihood of energy deficits, and this metabolic phenotype correlated with inflammatory markers rather than sedation or level of consciousness.
– Early, serial indirect calorimetry could identify patients at highest risk and inform targeted nutritional strategies, but interventional data are needed to determine if tailored feeding preserves muscle and improves outcomes.
