title: Effect of Replacing Animal Protein with Plant Protein on Glycemic Control in Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
abstract: Previous research on the effect of replacing sources of animal protein with plant protein on glycemic control has been inconsistent. We therefore conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the effect of this replacement on glycemic control in individuals with diabetes. We searched MEDLINE, EMBASE, and Cochrane databases through 26 August 2015. We included RCTs ≥ 3-weeks comparing the effect of replacing animal with plant protein on HbA1c, fasting glucose (FG), and fasting insulin (FI). Two independent reviewers extracted relevant data, assessed study quality and risk of bias. Data were pooled by the generic inverse variance method and expressed as mean differences (MD) with 95% confidence intervals (CIs). Heterogeneity was assessed (Cochran Q-statistic) and quantified (I²-statistic). Thirteen RCTs (n = 280) met the eligibility criteria. Diets emphasizing a replacement of animal with plant protein at a median level of ~35% of total protein per day significantly lowered HbA1c (MD = -0.15%; 95%-CI: -0.26, -0.05%), FG (MD = -0.53 mmol/L; 95%-CI: -0.92, -0.13 mmol/L) and FI (MD = -10.09 pmol/L; 95%-CI: -17.31, -2.86 pmol/L) compared with control arms. Overall, the results indicate that replacing sources of animal with plant protein leads to modest improvements in glycemic control in individuals with diabetes. Owing to uncertainties in our analyses there is a need for larger, longer, higher quality trials.
  
  
  BACKGROUND
  ClinicalTrials.gov registration number: NCT02037321.
authors.affiliation: Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Center, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. effie.viguiliouk@mail.utoronto.ca.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. effie.viguiliouk@mail.utoronto.ca.
authors.forename: Effie
authors.initials: E
authors.lastname: Viguiliouk
authors.affiliation: Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Center, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. sarahe.stewart@mail.utoronto.ca.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. sarahe.stewart@mail.utoronto.ca.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Stewart
authors.affiliation: Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Center, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. viranda.jayalath@mail.utoronto.ca.|Department of Surgical Oncology, Princess Margaret Cancer Center, University Health Network, Toronto, ON M5G 2C4, Canada. viranda.jayalath@mail.utoronto.ca.|Undergraduate Medical Education, University of Toronto, Toronto, ON M5S 2E8, Canada. viranda.jayalath@mail.utoronto.ca.
authors.forename: Viranda H
authors.initials: VH
authors.lastname: Jayalath
authors.affiliation: Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Center, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. alena.ng@mail.utoronto.ca.
authors.forename: Alena Praneet
authors.initials: AP
authors.lastname: Ng
authors.affiliation: Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Center, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. smirrahimi@qmed.ca.|School of Medicine, Faculty of Health Sciences, Queen's University, Kingston, ON K7L 3N6, Canada. smirrahimi@qmed.ca.
authors.forename: Arash
authors.initials: A
authors.lastname: Mirrahimi
authors.affiliation: Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Center, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. rdesouz@mcmaster.ca.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. rdesouz@mcmaster.ca.|Department of Clinical Epidemiology &amp; Biostatistics, Faculty of Health Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada. rdesouz@mcmaster.ca.
authors.forename: Russell J
authors.initials: RJ
authors.lastname: de Souza
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. anthony.hanley@utoronto.ca.|Leadership Sinai Centre for Diabetes, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada. anthony.hanley@utoronto.ca.|Department of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. anthony.hanley@utoronto.ca.|Dalla Lana School of Public Health, University of Toronto, Toronto, ON M5S 2E8, Canada. anthony.hanley@utoronto.ca.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Hanley
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. richard.bazinet@utoronto.ca.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Bazinet
authors.affiliation: Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Center, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. BlancoMejiaS@smh.ca.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. BlancoMejiaS@smh.ca.
authors.forename: Sonia
authors.initials: S
authors.lastname: Blanco Mejia
authors.affiliation: Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Center, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. LeiterL@smh.ca.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. LeiterL@smh.ca.|Department of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. LeiterL@smh.ca.|Division of Endocrinology and Metabolism, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. LeiterL@smh.ca.|Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. LeiterL@smh.ca.
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Leiter
authors.affiliation: Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Center, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. JosseRG@smh.ca.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. JosseRG@smh.ca.|Department of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. JosseRG@smh.ca.|Division of Endocrinology and Metabolism, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. JosseRG@smh.ca.|Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. JosseRG@smh.ca.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Josse
authors.affiliation: Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Center, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. cyril.kendall@utoronto.ca.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. cyril.kendall@utoronto.ca.|College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK S7N 5A2, Canada. cyril.kendall@utoronto.ca.
authors.forename: Cyril W C
authors.initials: CW
authors.lastname: Kendall
authors.affiliation: Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Center, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. NutritionProject@smh.ca.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. NutritionProject@smh.ca.|Department of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. NutritionProject@smh.ca.|Division of Endocrinology and Metabolism, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. NutritionProject@smh.ca.|Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. NutritionProject@smh.ca.
authors.forename: David J A
authors.initials: DJ
authors.lastname: Jenkins
authors.affiliation: Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Center, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. john.sievenpiper@utoronto.ca.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON M5S 2E8, Canada. john.sievenpiper@utoronto.ca.|Division of Endocrinology and Metabolism, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. john.sievenpiper@utoronto.ca.|Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON M5C 2T2, Canada. john.sievenpiper@utoronto.ca.
authors.forename: John L
authors.initials: JL
authors.lastname: Sievenpiper
mesh_terms: D000818:Animals; D001786:Blood Glucose; D003920:Diabetes Mellitus / Q000178:diet therapy*; D004044:Dietary Proteins; D006801:Humans; D008460:Meat; D010940:Plant Proteins; D016032:Randomized Controlled Trials as Topic
chemical_list: D001786:Blood Glucose; D004044:Dietary Proteins; D010940:Plant Proteins
keywords: animal protein; diabetes; glycemic control; plant protein