Comparison 1. All‐cause mortality.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Glutamine vs control	3	111	Risk Ratio (M‐H, Fixed, 95% CI)	0.25 [0.08, 0.78]
1.1 Enteral	2	85	Risk Ratio (M‐H, Fixed, 95% CI)	0.23 [0.06, 0.93]
1.2 Parenteral	1	26	Risk Ratio (M‐H, Fixed, 95% CI)	0.29 [0.04, 2.27]
2 Ornithine α‐ketoglutarate vs control	3	155	Risk Ratio (M‐H, Fixed, 95% CI)	0.93 [0.37, 2.36]
2.1 Enteral	3	155	Risk Ratio (M‐H, Fixed, 95% CI)	0.93 [0.37, 2.36]
3 Branched‐chain amino acids vs control	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected
3.1 Parenteral	1		Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
4 Fish oil vs control	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected
4.1 Enteral	1		Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
5 Combined immunonutrients vs control	4	163	Risk Ratio (M‐H, Fixed, 95% CI)	1.10 [0.47, 2.60]
5.1 Enteral	4	163	Risk Ratio (M‐H, Fixed, 95% CI)	1.10 [0.47, 2.60]