Olestra Containing Foods and Weight Loss and Weight Maintenance
Condition: Obesity
MeSH terms: Weight Loss
Study type: Interventional

Summary: 
      This study will be conducted over three phases. Phase I will be a 16-week weight lass phase.
      Phase II will be a 52-week maintenance phase. Phase III will be a follow-up phase. We will
      test three diet regimens: 1) an olestra group who will receive a weight-reducing diet that
      includes olestra-containing products; 2) a triglyceride group who will receive the same
      weight-reducing diet but with foods made with triglyceride (regular fat); 3) a low-fat group
      will be instructed to consume a diet made of traditionally low-fat foods that ate available
      in grocery stores (no olestra foods). These groups will be re-randomized for the maintenance
      phase and again assigned to one of the three weight loss regimens described above: olestra,
      triglyceride, or low-fat. In the double-blinded experimental design, groups receiving olestra
      foods will not be informed of the nutrient contents of the foods or told what fat substitute
      is used in the preparation. (The consent form will state that a new fat-substitute may be
      used in the study foods.) During a "run-in" phase, olestra versus regular-fat food sensory
      and tolerance tests will be conducted.
    

Detailed description: 
      During Phase I, the three groups will attend mandatory, 1 hour, bi-weekly group meetings.
      Participants will keep food records for 2 weekdays and 1 weekend day during each 2 week
      period as well as keeping exercise, snack and sleep logs daily. At each meeting, research
      staff will collect the completed food records and logs and new forms will be distributed. At
      weeks 8 and 16 of active weight loss, participants will repeat the assessments (blood tests,
      body composition, and questionnaires) conducted at baseline to determine treatment-induced
      changes in each of the dependent measures.

      During phase II, all of the groups will participate in group meetings held 1 month after
      beginning maintenance and quarterly over 52 weeks. Dependent upon group, participants will
      pick-up foods bi-weekly and body weight will be assessed every 4 weeks. The full battery of
      assessments will be conducted at 26 weeks and at the end of the maintenance phase at 52
      weeks.

      Participants will be 180 adults (male and female) between 25 and 50 years of age. The study
      is designed to answer questions involving an adult population. Participants must be
      interested in losing weight. Participants must have a body mass index between 30 and 33
      because this study is designed to answer questions investigating overweight individuals that
      are not morbidly obese. Participants with preliminary eligibility, determined via phone
      screening, will be invited to the clinic for a more in-depth screening including demographic
      and medical history questionnaires and psychosocial measures. Participants will gibe their
      consent to provide this information via completing a screening consent form (a separate form
      from the study consent form). Once this secondary eligibility is determined, a study consent
      form will be completed, and participants will undergo a baseline screening of physical
      measures, blood tests (CBC, SMA-20), body composition assessment (via bioelectrical
      impedance), and complete additional psychosocial questionnaires. Any participants found to be
      ineligible as a result of these measures will not be permitted to continue in the study, but
      will be referred for medical care if appropriate. Participants deemed eligible will proceed
      to the weight loss phase.
    

Intervention name(s): dietary education; dietary education and provided full fat snack foods; dietary education and provided fat free snack foods
Intervention type(s): Behavioral; Behavioral; Behavioral
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double
Primary purpose: Treatment