Jin 1999a.

Methods	Randomised clinical trial, China
Participants	92 hospitalised adults diagnosed with adenocarcinoma of the GI tract deemed operable by a consultant surgeon, at nutritional risk due to serum albumin < 30 g/L or a recent weight loss of > 10% body weight Male:Female = 58:34 Mean age = 57 years Exclusion:congestive heart failure, obstructive lung disease, metabolic diseases, clinically‐evident cirrhotic liver disease or renal disease
Interventions	Experimental group 1: Parenteral nutrition: Preoperative PN provided 35 kcal/kg a day. Non‐protein caloric content was divided between dextrose (60%) and lipids (40%) (Intralipid; Kabi Pharmacia, Sweden). Crystalline amino acids (7% Vamin; Kabi Pharmacia, Sweden) were provided at a calorie:nitrogen ratio of 150:1 g of nitrogen (0.23 g of nitrogen a kilogram a day). Each day, the nutrient mixture, which was prepared in ethyl vinyl acetate bags, was infused through a subclavian polyurethane catheter over 24 hrs by an infusion pump. The catheter was inserted using a strict aseptic procedure in the operating room.(n = 23) Control group 1: No intervention(n = 23)
Outcomes	Weight, complications, postoperative mortality and nutritional parametres including serum albumin (g/L), serum transferrin (g/L), nitrogen balance (g/L)
Study dates	Not stated
Notes	We could obtain no contact information for the authors. Same trial as Jin 1999b but with the experimental and control group that did not received chemotherapy.
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	High risk	Participants and personnel were not blinded.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Outcome assessors were not blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants completed the study.
Selective reporting (reporting bias)	Low risk	The protocol could not be obtained, but the trial reported on serious adverse events and mortality.
For‐profit bias	Unclear risk	It was unclear how the trial was funded.
Other bias	Low risk	The trial appeared to be free of other components that could put it at risk of bias.