title: Increasing the effectiveness of the Diabetes Prevention Program through if-then plans: study protocol for the randomized controlled trial of the McGill CHIP Healthy Weight Program.
abstract: BACKGROUND
  The Diabetes Prevention Program (DPP) is highly effective in promoting weight loss in overweight and obese individuals. However, one-on-one DPP sessions are costly. As a cost-saving alternative, a group version of the DPP, called Group Lifestyle Balance program (GLB), has been developed but has been shown to be less effective. The aim of this two-arm parallel randomized controlled trial is to increase the effectiveness of the GLB by integrating habit formation techniques, namely if-then plans and their mental practice, into the program.
  
  
  METHODS
  A total of 154 participants will be randomized to a standard or enriched GLB program. For the enriched GLB program, if-then plans and their mental practice will be integrated into the standard GLB program. Participants will be overweight or obese men and women (BMI of 28 to 45 kg/m2, waist circumference ≥ 88 for women, ≥ 102 for men, 18 to 75 years of age) who do less than 200 minutes of self-reported moderate or vigorous exercise per week. Measures will be completed at baseline, 3 months, post-intervention (12 months), and 12 months post-intervention (24 months). The primary outcome measure is weight loss at 3, 12, and 24 months. Secondary outcomes include percent reaching weight loss goal, physical activity at 3, 12, and 24 months, and weight-related risk factors (waist circumference, hemoglobin A1c, systolic/diastolic blood pressure, total cholesterol/HDL ratio). Standardized training of the life-style coaches, use of standardized manuals, and audio taping and reviewing of the sessions will ensure intervention fidelity.
  
  
  CONCLUSIONS
  The study will provide evidence-based data on the effectiveness of an enhanced GLB intervention in promoting weight loss and in reducing weight-related risk factors for chronic health problems. Ethical clearance has been received from the Research Ethics and Compliance Board of the Faculty of Medicine Research and Graduate Studies Office at McGill University (Montreal, Canada).
  
  
  BACKGROUND
  ClinicalTrials.gov Identifier: NCT02008435. Registered 6 December 2013.
authors.affiliation: Department of Psychology, McGill University, 1205 Dr, Penfield Avenue, Montreal H3A 1B1, QC, Canada. barbel.knauper@mcgill.ca.
authors.forename: Bärbel
authors.initials: B
authors.lastname: Knäuper
authors.forename: Elena
authors.initials: E
authors.lastname: Ivanova
authors.forename: Zhen
authors.initials: Z
authors.lastname: Xu
authors.forename: Melodie
authors.initials: M
authors.lastname: Chamandy
authors.forename: Ilka
authors.initials: I
authors.lastname: Lowensteyn
authors.forename: Lawrence
authors.initials: L
authors.lastname: Joseph
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Luszczynska
authors.forename: Steven
authors.initials: S
authors.lastname: Grover
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001521:Behavior Therapy; D002170:Canada; D003920:Diabetes Mellitus / Q000209:etiology / Q000517:prevention & control*; D015444:Exercise; D005260:Female; D006184:Habits; D015438:Health Behavior; D006293:Health Promotion; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000628:therapy*; D050177:Overweight; D012107:Research Design; D012307:Risk Factors; D055105:Waist Circumference; D015431:Weight Loss; D061217:Weight Reduction Programs; D055815:Young Adult