title: Commercial Very Low Energy Meal Replacements for Preoperative Weight Loss in Obese Patients: a Systematic Review.
abstract: This systematic review assessed feasibility and effectiveness of preoperative meal replacements to improve surgical outcomes for obese patients.
  
  
  
  PRISMA guidelines were followed and electronic databases searched for articles between January 1990 and March 2015.
  
  
  
  Fifteen studies (942 participants including 351 controls) were included, 13 studies (n = 750) in bariatric patients. Adverse effects and dropout rates were minimal. Ten out of 14 studies achieved 5-10 % total weight loss. Six of six studies reporting liver volume achieved 10 % reduction. Endpoints for perioperative risks and outcomes were too varied to support definitive risk benefit.
  
  
  
  Commercial meal replacements are feasible, have minimal side effects and facilitate weight loss and liver shrinkage in free-living obese patients awaiting elective surgery. A reduction in surgical risk is unclear.
authors.affiliation: Department of Nutrition and Dietetics, Royal Brisbane & Women's Hospital, Brisbane, QLD, Australia. lynda.ross@griffith.edu.au.|Menzies Health Institute Queensland, Griffith University, Gold Coast campus, Southport, QLD, Australia. lynda.ross@griffith.edu.au.
authors.forename: Lynda J
authors.initials: LJ
authors.lastname: Ross
authors.affiliation: Department of Nutrition and Dietetics, Royal Brisbane & Women's Hospital, Brisbane, QLD, Australia.
authors.forename: Siobhan
authors.initials: S
authors.lastname: Wallin
authors.affiliation: Department of Nutrition and Dietetics, Royal Brisbane & Women's Hospital, Brisbane, QLD, Australia.|School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, QLD, Australia.
authors.forename: Emma J
authors.initials: EJ
authors.lastname: Osland
authors.affiliation: Sunnybank Obesity Centre and South East Queensland Surgery (SEQS), Sunnybank, QLD, Australia.|Mayne Medical School, School of Medicine, University of Queensland, Brisbane, QLD, Australia.|Faculty of Health Sciences and Medicine, Bond University, Gold Coast, QLD, Australia.|Faculty of Health Sciences, Mathematics and Computing, Australian Centre for Sustainable Catchments, University of Southern Queensland, Toowoomba, QLD, Australia.|Faculty of Health Science, Bolton University, Bolton, Lancashire, UK.
authors.forename: Muhammed Ashraf
authors.initials: MA
authors.lastname: Memon
mesh_terms: D050110:Bariatric Surgery; D004038:Diet, Reducing / Q000009:adverse effects / Q000379:methods*; D002149:Energy Intake / Q000502:physiology; D006801:Humans; D009767:Obesity, Morbid / Q000503:physiopathology / Q000601:surgery*; D011300:Preoperative Care / Q000379:methods; D015431:Weight Loss / Q000502:physiology*
keywords: Meal replacements; Preoperative weight loss; Surgical outcomes; Very low energy diet