Increasing the Effectiveness of the Diabetes Prevention Program

Increasing the Effectiveness of the Diabetes Prevention Program Through If-then Plans and Mental Practice: A Parallel Randomized Trial

The Diabetes Prevention Program (DPP) is highly effective in promoting weight loss in overweight and obese individuals (e.g., 7% average loss of body weight), and thereby reducing the risk of developing weight-related health consequences. One-on-one DPP sessions, however, are costly and the group-delivered DPP version, the Group Lifestyle Balance program (GLB), is less effective (4% average loss of body weight). 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. 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.

Please see brief summary.

Inclusion Criteria:

• men and women
• ages of 18 and 75
• overweight or obese (BMI 28-45 kg/m2)
• sedentary (< 200 min/week of moderate or vigorous exercise)
• waist circumference of >= 88cm for women and >= 102cm for men

Exclusion Criteria:

• diabetes (hemoglobin A1c < 7.0%).
• taking the medication metformin (used for treating pre-diabetes or diabetes)
• having been pregnant in the past 6 months or planning on becoming pregnant in the next 2 years
• currently undergoing treatment for cancer
• using medication that affects body weight (e.g., loop diuretics)
• being unable to participate in regular moderate physical activity
• having severe uncontrolled hypertension (> 190/100mm Hg)
• being unable to communicate in English or French
• being diagnosed with bulimia nervosa, currently active major depression, or other severe psychiatric disease (including dementia);
• suffering from a heart attack, stroke, or heart failure within the past 6 months
• experiencing excessive weight loss (more than 10 pounds or 4.54 kilograms) in the past 3 months
• currently participating in another weight loss program
• having had bariatric surgery in the past 2 years or plans on getting it in the near future
• planning on moving away from Montreal within the next year
• having another member of one's household enrolled in the program.