Advances in Intermittent Fasting Applications for Critically Ill Patients

Enteral nutrition remains the standard approach for nutritional support in critically ill patients, with established benefits for immune function and recovery. Intermittent fasting, a dietary strategy characterized by extended fasting intervals, has emerged as a potential adjunctive therapy. IF may induce beneficial metabolic responses such as autophagy activation and ketogenesis, contributing to improved glucose regulation, reduced intestinal permeability, modulation of gut microbiota, enhanced insulin sensitivity, and preservation of muscle mass. Unlike prolonged fasting, IF elicits these effects without causing sustained caloric deprivation. This review summarizes the current evidence regarding the physiological mechanisms, implementation strategies, clinical outcomes, and safety considerations of IF in the intensive care setting to provide a theoretical basis for further validation of the safety efficacy of the intermittent fasting paradigm for use in the ICU.