Beattie 2000.

Study characteristics
Methods	RCT. Parallel design with 2 arms. Duration: 10 weeks. Location: single centre in the UK.
Participants	Inclusion criteria: adults resuming oral food intake after surgery with BMI < 20 kg/m², TSF or MAMC < 15th percentile or > 5% weight loss. All participants had an MNA score 20 or less. Exclusion criteria: requiring parenteral nutrition, pregnant or lactating, with terminal illness, decompensated liver or renal disease. Number randomised: 101 adults (both men and women). Gender split: 41 females, 60 males. Age: mean (SD); intervention group 54.4 (19.4) years; control group 62.4 (10.9) years. Nutritional status: on inclusion to study defined as mild (BMI <20 kg/m2), moderate (BMI <18 kg/m2), severe (BMI <16 kg/m2) normal (BMI 20‐25 kg/m2), overweight (BMI >25 kg/m2); intervention group severe 1, moderate 5, mild 29, normal 13, overweight 4; control group severe 2, moderate 9, mild 19, normal 16, overweight 3. nb. participants with normal or overweight BMI had weight loss >5% at inclusion.
Interventions	Intervention: participants received dietary advice and ONS in the form of routine nutritional management and 400 mL of a 1.5 kcal/mL nutritional supplement. Control: participants received dietary advice alone in the form of routine nutritional management.
Outcomes	Survival*, weight*, BMI*, MAMC*, TSF*, handgrip strength*, complication rate, wound infection, chest infection, antibiotic use, QoL.
Publication details	Language: English. Funding: this study was funded by Abbott Laboratories. Publication status: peer‐reviewed journal.
Notes	Routine nutritional management provided by more than one dietitian and not described in the paper. Information on quality obtained from authors. Information on QoL not added to meta‐analyses as only scores for physical and mental QoL were provided in the manuscript ‐ global QoL missing.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation was performed using a computer‐generated list of random numbers.
Allocation concealment (selection bias)	Low risk	The allocation was not concealed physically but the list of numbers was not consulted until the participant was recruited.
Blinding (performance bias and detection bias) Clinical outcomes	Low risk	The paper states that assessors were not blinded to treatment. However, it unlikely that morbidity is influenced by lack of blinding.
Blinding (performance bias and detection bias) Functional outcomes	Unclear risk	No functional outcomes reported.
Blinding (performance bias and detection bias) Nutritional outcomes	High risk	The paper states that assessors were not blinded to treatment. Nutritional status and QoL outcomes can be influenced by assessors knowing group allocations.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not blinded and likely that researchers and participants were aware of group allocation as this was a nutritional intervention. It is possible that assessment of some outcomes was influenced by lack of blinding.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Judged to be unclear because low risk for clinical outcomes and high risk for nutritional and QoL outcomes.
Incomplete outcome data (attrition bias) All outcomes	Low risk	8/101 (8%) attrition, 3 drop outs in intervention group (advice plus supplements) (transferred to intensive care unit n = 1, required artificial nutritional support n = 2) and 5 dropouts in control group (routine nutritional management group) (lost to follow‐up n = 2, required artificial nutritional support n = 3).
Selective reporting (reporting bias)	Unclear risk	No study protocol identified, thus unable to judge whether all planned outcomes were reported. Data for analysis were extracted from the paper. Additional information on study quality obtained from authors. QoL data were not complete, only physical and mental health data provided
Other bias	Unclear risk	Baseline variables provided, but groups not similar ‐ group receiving advice plus supplements was younger by almost 10 years than the advice only group. Routine nutritional management provided by more than one dietitian and not described in the paper.