Intermittent versus continuous enteral nutrition in critically ill patients: an updated systematic review and meta-analysis of randomized controlled trials

Background Both intermittent enteral nutrition (IEN) and continuous enteral nutrition (CEN) are used to provide nutritional support to critically ill patients. However, their comparative effects on gastrointestinal tolerance and clinical outcomes remain uncertain. Objectives We conducted an updated systematic review and meta-analysis of randomized controlled trials (RCTs) to compare the efficacy and safety of IEN versus CEN in critically ill patients. Methods We performed a comprehensive literature search of PubMed, Embase, Scopus, and the Cochrane Library from inception through December 10, 2025, to identify RCTs comparing IEN and CEN in critically ill adults. The primary outcome was all-cause mortality in the intensive care unit (ICU). Secondary outcomes included gastrointestinal complications, length of ICU stay, and achievement of nutritional goals. Pooled risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs) were calculated using random-effects or fixed-effects models as appropriate. Subgroup analyses were performed according to mechanical ventilation status. Results Twenty-two RCTs comprising 1,662 critically ill patients (IEN, n = 816; CEN, n = 846) were included. Compared with CEN, IEN was associated with a significantly higher incidence of diarrhea (RR 1.56, 95% CI 1.23 to 1.98, I 2 = 19%) and abdominal distension (RR 1.68, 95% CI 1.10 to 2.57, I 2 = 18%), as well as prolonged ICU length of stay (MD 0.91, 95% CI 0.41 to 1.41, I 2 = 0%). Conversely, IEN was associated with a lower incidence of constipation (RR 0.74, 95% CI 0.57 to 0.97, I 2 = 0%). These effects were more pronounced in mechanically ventilated patients, whereas no statistically significant differences were observed in non-ventilated patients. No significant differences were identified between the two strategies regarding ICU mortality, vomiting, gastric retention, aspiration pneumonia, or achievement of nutritional goals. Conclusion This updated meta-analysis demonstrates that IEN is associated with increased rates of diarrhea and abdominal distension and prolonged ICU length of stay compared with CEN, particularly among mechanically ventilated patients. Although IEN reduces the incidence of constipation, CEN may be the preferable feeding strategy for most critically ill patients. Individualized approaches considering patient-specific factors and clinical context are warranted. Further high-quality trials are needed to identify patient subgroups who might benefit from IEN. Systematic review registration https://osf.io/krs8v .