title: A randomised trial comparing low-fat diets differing in carbohydrate and protein ratio, combined with regular moderate intensity exercise, on glycaemic control, cardiometabolic risk factors, food cravings, cognitive function and psychological wellbeing in adults with type 2 diabetes: Study protocol.
abstract: BACKGROUND
  Hypocaloric low-fat diets, high in protein with moderate carbohydrate (HP) can enhance weight loss, improve glycaemic control and improve cardiometabolic health risk factors in type 2 diabetes mellitus (T2DM). However, it is unclear whether the metabolic benefits observed during weight loss are sustained during energy-balance and weight maintenance. Furthermore, there is a lack of evidence regarding the effect of HP diets on food cravings, cognitive function and psychological wellbeing in T2DM, despite carbohydrate food cravings, cognitive impairment and depression being associated with hyperglycaemia.
  
  
  METHODS
  Overweight/obese adults with T2DM were randomised to consume either a HP diet (n=32, ~32% protein, 33% carbohydrate, 30% fat) or a higher-carbohydrate diet (HC, n=29, ~22% protein, 51% carbohydrate, 22% fat) for 24 weeks with 30 min of moderate intensity exercise five days/week for the study duration. There were 2 phases: a 12 week weight loss phase followed by a 12 week weight maintenance phase. Primary outcome was glycaemic control (glycosylated haemoglobin; HbA1c). Secondary outcomes were cardiometabolic risk factors (body composition, fasting blood pressure, blood lipids, glucose, insulin and C-reactive protein), food cravings, cognitive function (memory; psychomotor and executive function and psychological well-being. Outcomes were measured at baseline and the end of each 12-week intervention phase. Data will be analysed as intention-to-treat using linear mixed effects models.
  
  
  CONCLUSIONS
  This study will examine the effects of two dietary interventions on health outcomes in T2DM during weight loss and notably following weight maintenance where there is a paucity of evidence.
authors.affiliation: Alliance for Research in Exercise, Nutrition and Activity, Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia. Electronic address: nerylee.watson@mymail.unisa.edu.au.
authors.forename: Nerylee Ann
authors.initials: NA
authors.lastname: Watson
authors.affiliation: Alliance for Research in Exercise, Nutrition and Activity, Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia. Electronic address: Kate.Dyer@unisa.edu.au.
authors.forename: Kathryn Ann
authors.initials: KA
authors.lastname: Dyer
authors.affiliation: Alliance for Research in Exercise, Nutrition and Activity, Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia. Electronic address: Jon.Buckley@unisa.edu.au.
authors.forename: Jonathan David
authors.initials: JD
authors.lastname: Buckley
authors.affiliation: Food and Nutrition, Commonwealth Scientific and Industrial Research Organisation, PO Box 10041, Adelaide, SA 5000, Australia. Electronic address: grant.brinkworth@csiro.au.
authors.forename: Grant David
authors.initials: GD
authors.lastname: Brinkworth
authors.affiliation: Alliance for Research in Exercise, Nutrition and Activity, Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia. Electronic address: Alison.Coates@unisa.edu.au.
authors.forename: Alison Mary
authors.initials: AM
authors.lastname: Coates
authors.affiliation: Alliance for Research in Exercise, Nutrition and Activity, Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia. Electronic address: Gaynor.Parfitt@unisa.edu.au.
authors.forename: Gaynor
authors.initials: G
authors.lastname: Parfitt
authors.affiliation: Clinical Nutrition Research Centre, School of Biomedical Sciences and Pharmacy, University of Newcastle, University Drive, Callaghan, NSW 2308, Australia. Electronic address: Peter.Howe@newcastle.edu.au.
authors.forename: Peter Ranald Charles
authors.initials: PRC
authors.lastname: Howe
authors.affiliation: Food and Nutrition, Commonwealth Scientific and Industrial Research Organisation, PO Box 10041, Adelaide, SA 5000, Australia. Electronic address: manny.noakes@csiro.au.
authors.forename: Manny
authors.initials: M
authors.lastname: Noakes
authors.affiliation: School of Psychology, University of Leeds, Leeds LS2 9JT, United Kingdom. Electronic address: L.Dye@leeds.ac.uk.
authors.forename: Louise
authors.initials: L
authors.lastname: Dye
authors.affiliation: School of Psychology, University of Leeds, Leeds LS2 9JT, United Kingdom. Electronic address: H.K.Chadwick@leeds.ac.uk.
authors.forename: Helen
authors.initials: H
authors.lastname: Chadwick
authors.affiliation: Alliance for Research in Exercise, Nutrition and Activity, Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia. Electronic address: Karen.Murphy@unisa.edu.au.
authors.forename: Karen Joy
authors.initials: KJ
authors.lastname: Murphy
mesh_terms: D001786:Blood Glucose; D001837:Body Weights and Measures; D002097:C-Reactive Protein; D003071:Cognition; D066249:Craving; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000523:psychology / Q000628:therapy*; D018752:Diet, Fat-Restricted / Q000379:methods*; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D015444:Exercise; D006442:Glycated Hemoglobin; D006304:Health Status; D006801:Humans; D008055:Lipids / Q000097:blood; D008603:Mental Health; D009765:Obesity / Q000453:epidemiology / Q000628:therapy; D050177:Overweight / Q000453:epidemiology* / Q000523:psychology / Q000628:therapy*; D011788:Quality of Life; D012107:Research Design; D012307:Risk Factors; D061217:Weight Reduction Programs
chemical_list: D001786:Blood Glucose; D002097:C-Reactive Protein; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D006442:Glycated Hemoglobin; D008055:Lipids
keywords: Cardiometabolic; Cognitive; Diabetes; Glycemic; Protocol; Psychological