Efficacy of Parent-Child Dieting Plans Incorporating Medifast Meal Replacements for Weight Loss
Condition: Obesity
Study type: Interventional

Summary: 
      1. Does a joint parent-child dieting approach, as opposed to an individually-based
           approach, improve weight loss outcomes?

        2. Is a diet which includes Medifast meal replacements as efficacious as a non-supplemented
           Food Guide Pyramid-based diet (reference diet) in achieving better adherence to the
           diet, initial weight loss, reduction in % body fat, and weight maintenance?

        3. Does regular use of Medifast meal replacements, in conjunction with a Food Guide
           Pyramid-based diet, result in significantly better compliance, greater dietary
           satisfaction, dietary quality, and palatability than the reference diet?

        4. Do children who have lost weight using Medifast meal replacements, as an adjunct to a
           Food Guide Pyramid-based diet, achieve health benefits compared to baseline values and
           are these health benefits greater than those obtained following the reference diet?
    

Detailed description: 
      Weight Loss Phase: This phase will take place between week 0 and week 26 (6 months).
      Participants will be randomly assigned to one of two weight loss treatment groups:

        1. Medifast meal replacement diet group (3 supplements per day) plus food-based diet

        2. Reference diet group (Food Guide Pyramid-based diet)

      Participants will be further randomly assigned to one of two parent-child approaches:

        1. Dieting child with one dieting parent

        2. Dieting child without dieting parent Although it is encouraged to have both parents
           involved in the child's care, only one parent will be permitted to be dieting as a part
           of the study along with the child so that we can more cleanly assess the effects of a
           parent dieting without confounding effects of some families having two parents dieting.
           Both groups will attend separate biweekly educational lessons during the weight loss
           phase (same curriculum and teacher). Data collection visits will occur at baseline, week
           12, and transition. There are a total of 31 visits for a child participating in this
           study, and 30.for a parent participating by dieting with their child.

      Transition Phase: Transition to a maintenance diet will be individually timed by participant
      attainment of goal "healthy" weight (BMI≤ 25) or week 26, whichever comes first.

      Maintenance Phase: This phase will occur after completion of weight loss or between weeks 27
      and 78 (12 months). Groups will attend separate educational lessons (same curriculum and
      teacher) once every 4 weeks. The Medifast group will reduce supplements to 2 per day with a
      larger portion of calories from whole foods. The reference diet group will remain on a
      food-based (no supplements) maintenance diet for the entire 52+ week maintenance period. Data
      collection visits will occur at weeks 26 and 52.
    

Intervention name(s): Medifast FIT! for Kids; standard recommendations for dietary intake in children; both diet plans with and without a parent dieting
Intervention type(s): Behavioral; Behavioral; Behavioral
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment