Wood 1989a.

Methods	Randomised clinical trial, USA
Participants	55 hospitalised adult men undergoing routine major surgery, at nutritional risk due to major surgery Male:Female = 55:0 Mean age = 54 years Exclusion criteria: none stated
Interventions	Experimental group 1: TPN (90 g of crystalline amino acids, 3000 calories as glucose a day) from 2 weeks prior to surgery until 1 week after surgery (n = 10) Experimental group 2: parenteral nutrition 90 g amino acids a day (n = 15) Experimental group 3: parenteral nutrition: peripheral parenteral nutrition (90 g amino acids plus 1600 calories, 60% as fat a day)(n =15) Control group: treatment as usual (100 g glucose) (n = 15)
Outcomes	Nitrogen balance, maintenance of body cell mass, serum albumin levels, exercise capacity
Study dates	Not stated
Notes	Group 1 could not be used in the analysis, since this group was not properly randomised (they had to have a certain degree of malnutrition, before being randomised to this group).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not described
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not described
Selective reporting (reporting bias)	Unclear risk	No protocol could be obtained, and the trial did not report mortality or serious adverse events.
For‐profit bias	Low risk	The trial was funded by the Veterans Affairs Administration.
Other bias	Low risk	The trial appeared to be free of other components that could put it at risk of bias.