Project Impact: An Innovative Approach to Weight Loss Maintenance

Study Overview
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Brief Summary
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The major goal of this project is to evaluate an innovative approach to obesity. This study will determine if behavioral treatment can be improved by 1) implementing a primary focus on PA following initial weight loss treatment, and 2) using a novel, acceptance-based approach to the promotion of PA.

Detailed Description
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Most adults who engage in lifestyle modification find it difficult to maintain a high level of PA over the long-term, and most also find that weight regain is inevitable. The current portfolio of available interventions does not adequately address these challenges. This project is designed to test the effectiveness of an intervention that is specifically designed to enhance the ability to maintain, in the long-term, a level of PA high enough to achieve long-term weight loss maintenance. In the study, 300 obese adults will be recruited from the community and provided with 6 months of group-based, standard behavioral treatment for induction of weight loss (Phase I). A 6-month Phase I was chosen so that all participants will have sufficient time to accomplish initial weight loss before Phase II begins, allowing Phase II to truly be a test of weight loss maintenance. In Phase II, participants will receive one of three interventions, to be delivered for an additional 12 months: 1) behavioral treatment, with the standard emphasis on maintaining changes in diet and PA (BT), 2) behavioral treatment, with a primary emphasis on using these skills to maintain PA (BT-PA), or 3) acceptance-based behavioral treatment, with a primary emphasis on using these skills to maintain PA (ABT-PA). Assessments will be conducted at baseline, 6 months, 18 months (end of treatment), 24 months (6-month follow-up), and 36 months (18-month follow-up).

Official Title
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1R01DK100345-01A1: An Innovative, Physical Activity-focused Approach to Weight Loss Maintenance

Conditions
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Obesity, Weight Loss, Overweight

Intervention / Treatment
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* Behavioral: Gold Standard Behavior Therapy for Weight Loss
* Behavioral: Behavior Therapy for Weight Loss with Physical Activity Emphasis
* Behavioral: Acceptance-based Behavior Therapy for Weight Loss with PA emphasis


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Have a BMI between 27 and 45 kg/m2 Have the ability to engage in at least 15 minutes of moderate physical activity (e.g. brisk walking) Successfully complete all steps in the enrollment process, including attendance at all pre-randomization clinic visits and providing physician clearance Exclusion Criteria: Have a medical condition that prevents safe engagement in moderate-to-vigorous physical activity Are lactating, pregnant, or planning to become pregnant in the next three years Report recently beginning a course of or changing the dosage of prescription medications that can cause significant weight loss or weight gain Are participating in or plan to participate in another weight loss program in the next three years Have a primary family member or member of their household participating in the study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Standard Behavior Therapy for Weight Loss<br>Eighteen months of standard, group-based behavioral treatment for weight loss and weight loss maintenance. | Behavioral: Gold Standard Behavior Therapy for Weight Loss<br>* Group- based behavioral treatment for weight loss and weight loss maintenance, with a standard emphasis on diet (65% of session) and physical activity goals (25% of session). Other weight loss behaviors such as self monitoring will be covered in the remaining time (10% of session).<br>|
| Experimental: Behavior Therapy for Weight Loss with PA emphasis<br>Six months of standard, group-based behavioral treatment for weight loss and weight loss maintenance, followed by 12 months of standard, group-based behavioral treatment for weight loss and weight loss maintenance with a larger emphasis on physical activity goals. | Behavioral: Gold Standard Behavior Therapy for Weight Loss<br>* Group- based behavioral treatment for weight loss and weight loss maintenance, with a standard emphasis on diet (65% of session) and physical activity goals (25% of session). Other weight loss behaviors such as self monitoring will be covered in the remaining time (10% of session).<br>Behavioral: Behavior Therapy for Weight Loss with Physical Activity Emphasis<br>* Group-based behavioral treatment for weight loss and weight loss maintenance, with a larger emphasis on physical activity goals (65% of session) than eating-related goals (25% of session).Other weight loss behaviors such as self monitoring will be covered in the remaining time (10% of session).<br>|
| Experimental: Acceptance-based Behavior Therapy with PA emphasis<br>Six months of standard, group-based behavioral treatment for weight loss and weight loss maintenance, followed by 12 months of group-based behavior therapy with acceptance-based strategies, and a larger emphasis on physical activity goals. | Behavioral: Gold Standard Behavior Therapy for Weight Loss<br>* Group- based behavioral treatment for weight loss and weight loss maintenance, with a standard emphasis on diet (65% of session) and physical activity goals (25% of session). Other weight loss behaviors such as self monitoring will be covered in the remaining time (10% of session).<br>Behavioral: Acceptance-based Behavior Therapy for Weight Loss with PA emphasis<br>* Group-based, acceptance-based behavioral treatment for weight loss and weight loss maintenance, with a larger emphasis on physical activity goals (65% of session) than eating-related goals (25% of session).Other weight loss behaviors such as self monitoring will be covered in the remaining time (10% of session).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Body Weight | Objectively measured in the research clinic at each time point on a scale | Baseline, 6 months, 12 months, 18 months, 24 months, 36 months | 
| Change in Physical Activity | Objectively measured at each time point using wGT3X-BT accelerometers from Actigraph | Baseline, 6 months, 12 months, 18 months, 24 months, 36 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cardiorespiratory Fitness | Time taken to complete a half-mile walk on the treadmill. Shorter times indicate a greater level of cardiorespiratory fitness. | Baseline, 6 months, 12 months, 18 months, 24 months, 36 months | 
| Waist Circumference | Measured in the clinical horizontally at the umbilicus. | Baseline, 6 months, 12 months, 18 months, 24 months, 36 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obesity, Weight loss, Overweight