Kendell 1982.

Methods	Randomised controlled trial. Duration 6 weeks.
Participants	Adults (n = 24, 5 men and 19 women, mean age (SD) 25 years (8.1)), awaiting elective orthognathic surgery. 12 of 24 patients had a weight below IBW at inclusion. 100% follow up.
Interventions	Dietary instruction given verbally and in writing (n = 12) versus dietary instruction and an oral nutritional supplement (1.5 kcal/ml) to provide 50% of calculated energy requirements (n = 12).
Outcomes	Survival*, body weight*, MAUC, MAMC*, TSF*, serum chemistry and creatinine height index, macro and micronutrient intake, length of hospital stay.
Notes	Data not available from authors.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomised, method not stated.
Allocation concealment (selection bias)	Unclear risk	Method not stated.
Blinding (performance bias and detection bias) Clinical outcomes	Unclear risk	Not stated.
Blinding (performance bias and detection bias) Functional outcomes	Unclear risk	Not stated.
Blinding (performance bias and detection bias) Nutritional outcomes	Unclear risk	Not stated.
Incomplete outcome data (attrition bias) All outcomes	Low risk	100% follow up.
Selective reporting (reporting bias)	High risk	All outcomes reported but using general statements e.g. 'at each time interval, there no statistically significant differences in body weight, MAC, TSF and creatinine height index between the experimental and control groups'. Data presented in table as % deficit and data not available from the authors, therefore risk of bias due to partial reporting.
Other bias	High risk	Baseline variables not given, no information available from authors, not sure if groups similar at baseline.