Preference and Vegetarian Diet in Weight Loss Treatment
Condition: Obesity; Overweight
MeSH terms: Overweight; Weight Loss
Study type: Interventional

Summary: 
      We propose to add a treatment preference component to a larger study testing standard
      behavioral treatment (SBT) for weight loss without specific food group restriction vs
      standard behavioral treatment with gradual elimination of meat, poultry, and fish [a
      lacto-ovo-vegetarian (LOV) meal plan]. Eligible respondents will be randomized to one of two
      conditions: Treatment Preference-Yes/No. Individuals in the Treatment Preference-Yes will be
      assigned to their choice (SBT or SBT+LOV), those in Treatment Preference-No will be
      randomized to either SBT or SBT+LOV without regard to their preference.
    

Detailed description: 
      Both groups will receive the behavioral treatment program (32 sessions over 12 months) that
      has been used successfully in numerous behavioral weight loss studies conducted by Dr.
      Wing.42-44 The Treatment Preference-Yes and -No Groups will meet on separate evenings to
      avoid contamination across the conditions but will be led by the same multidisciplinary team
      (behavioral scientists, nutritionist, exercise physiologist). A brief description of elements
      common to both groups follows:

      Group Sessions: Groups will meet for 45-60 minutes weekly for Months 1-6, bi-weekly for
      Months 7-9, and monthly for Months 10-12. Participants will be weighed, receive nutritional
      and behavioral counseling, turn in the weekly diaries, and receive homework assignments at
      the sessions.

      Dietary Restrictions: Calorie Goal. Participants will receive an individualized calorie goal
      calculated from baseline body weight (1200 calories < 200 lbs; 1500 calories for > 200 lbs),
      used successfully in previous studies.42 Fat Goal. Fat gram goals will approximate 25% of
      calories.

      Physical Activity and Exercise: Participants will gradually increase their exercise,
      primarily walking, until they reach a minimum goal of 150 minutes per week (a caloric
      expenditure of 1000 calories/wk).

      Behavioral Strategies to Use in Changing Eating and Exercise Habits: The central features
      follow:

      Goal setting: daily/weekly goals for calorie and fat consumption, exercise time, and behavior
      change.

      Self-monitoring: systematically observing and recording one's behavior,45,46 which will be
      reviewed by the therapists, and written feedback will be provided to reinforce positive
      behaviors.

      Stimulus control: behavioral strategies designed to assist participants in altering their
      environment, minimize the cues that might trigger problematic behaviors, and add cues to
      increase activity.10 Problem solving: consists of 5 steps: identifying the problem;
      brainstorming solutions; evaluating the pros/cons of each potential solution; implementing
      the solution plan; and evaluating its success.47,48 Social assertion: use assertive skills in
      situations that may threaten their meeting eating/exercise goals.

      Feedback: therapists monitor the recorded behavior changes and provide
      feedback/encouragement.

      Cognitive strategies: taught how to recognize patterns of negative thought that can interfere
      with behavior change, how to counter these negative thoughts, and to use positive
      self-statements.

      Relapse prevention: recognize situations that place them at risk for lapses49 Maintenance:
      weight loss maintenance will be addressed, identify their own problems related to maintaining
      their new patterns of eating/exercising, develop problem-solving strategies.50-53
      Reinforcement: provide a magazine subscription to reinforce what is learned in each group.

      Ensuring dietary adequacy: diaries will be reviewed weekly for energy intake and expenditure
      and for nutrient adequacy. A dietitian will be part of the team reviewing the diaries.

      Incentives: will be given a monetary incentive for completing the paper-and-pencil
      instruments, Three-Day Food Record, and appointment for phlebotomy at 6, 12, and 18 months,
      and for completing the Final Visit.

      Educational Session on Risk of Cholelithiasis: A brief (~15-20 minutes with Questions and
      Answers to follow) educational session will be provided to study participants informing them
      of risk factors for cholelithiasis. The information presented will include predisposing risk
      factors (i.e., overweight/obesity at baseline, rapid weight loss, inadequate calorie and fat
      gram intake) and guidelines for reducing risk for cholelithiasis (i.e., safe rate of weekly
      weight loss, minimal caloric and fat gram intake per day). Participants will also be provided
      with an informational letter on cholelithisis risk factors and risk reduction and will be
      asked to sign this letter and return it to the staff on the project, to be placed in their
      study participant files.

      c.6.2. Dietary Intervention The treatment conditions will differ in eating plans and breadth
      of content (e.g., cooking classes, grocery shopping field trips) to better assist and support
      SBT+LOV participants develop their skills to implement and maintain the vegetarian meal plan.
      The differences are described below.

      c.6.2.1. Group 1: Dietary Intervention for the Standard Behavioral Treatment Group
      Participants in this condition will receive the standard behavioral treatment (SBT) described
      above. Food tastings will be held at the sessions and will focus on fat modified food
      products.

      c.6.2.2. Group 2: Dietary Intervention for the SBT+LOV Group Diet: In addition to SBT,
      participants will aim to eliminate all meat, poultry, and fish from their diet over the first
      6 weeks, and will be taught how to select appropriate substitutes for these foods, such as
      low- or no-fat dairy products (cheeses, milk), and protein-containing vegetable sources (soy
      products, legumes). The focus will be on the elimination of meat products as a means to
      reduce fat intake.

      Self-monitoring: In addition to energy intake/expenditure, record the number of meat meals
      eaten.

      Social support for dietary changes: One session will be offered: an overview of the eating
      pattern, how to merge different eating styles in one family, how to dine at the same
      restaurant, and how to attend family and social functions. Participants will be encouraged to
      bring family members. Family members will not be considered as subjects in the study and will
      not be asked to provide any information. They will be there as guests to receive information
      that may allow them to better support their family member who is participating in the study.

      Modeling: Practicing vegetarians will share strategies on making the transition to a
      vegetarian diet.

      Ensuring dietary adequacy: Menstruating females will be instructed to use vegetarian sources
      of iron (e.g., legumes, dark leafy greens, dried fruits) and to use iron supplements if their
      iron intake does not appear adequate on their reported diet. Hemoglobin will be measured at
      each assessment point and results will be reported to patient's physician if value is below
      normal. The cost for this test will be covered by the grant.
    

Intervention name(s): Standard Behavioral Treatment; SBT+LOV
Intervention type(s): Behavioral; Behavioral
Intervention description(s): Participants in this condition will receive the standard behavioral treatment (SBT) described above. Food tastings will be held at the sessions and will focus on fat modified food products.; The focus will be on the elimination of meat products as a means to reduce fat intake.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment