Cancer Dietary Objectives Study
Condition: Cancer; Heart Disease
MeSH terms: Heart Diseases
Study type: Interventional

Summary: 
      We hypothesize that adding beneficial high fiber foods to the diet will result in better
      overall dietary quality (measured by the Alternate Healthy Eating Index), which has been
      shown to be associated with cancer, than either reducing saturated fat, or a combination of
      high fiber and low saturated fat.
    

Detailed description: 
      Summary of Grant:

      Several studies have demonstrated that poor dietary quality is associated with obesity and
      certain cancers, such as gastrointestinal, colorectal, and hormonal cancers. Dietary
      interventions aimed at improving diet are plagued by poor adherence, possibly due to the
      complexity of changing multiple diet components. Complex public health messages are
      associated with worse adherence and reduced capacity to impact health outcomes. If a simple
      public health recommendation for diet was effective at changing multiple aspects of diet,
      adherence and impact could be maximized. However, research has yet to test which single
      dietary message has the greatest impact on overall diet quality, and consequently, potential
      for cancer and heart disease prevention. Thus far, dietary interventions have tested varying
      combinations of multiple recommendations; however, a single dietary recommendation may have a
      synergistic beneficial effect on other areas of diet, precluding the need to make the message
      overly complex.

      The present study compares 3 dietary change conditions that are hypothesized to have high
      potential for synergistic effects on other unaddressed areas of diet, and consequently
      overall dietary quality. Patients were randomized to one of three arms:

        1. low saturated fat diet (≤7% of total calories);

        2. high fiber diet (≥30 grams of total fiber per day);

        3. combination arm: low saturated fat and high fiber.

      Each participant was instructed to reduce calories by -500 kcal/day from his/her resting
      metabolic rate (RMR), but total calories was not less than 1200 calories per day.

      Additionally, Dr. Ira Ockene, professor of medicine, director of preventive cardiology
      program, generously offered to pay for blood draws and blood lipids and glucose analysis at
      each visit to make the study valuable from both cancer and heart disease research
      perspectives.

      Specific aims:

        1. Develop intervention materials. Intervention materials that specifically aid
           participants towards a low saturated fat or high fiber diet, or combination change
           developed for each condition.

        2. Preliminary test of intervention. We will calculate change in diet quality, lipids, body
           weight, waist circumference, and blood pressure at 3- and 6-months. We hypothesize that
           the single change conditions will produce more changes than the complex condition and
           that adding beneficial high fiber foods to the diet will result in improved dietary
           quality (measured by the Alternative Healthy Eating Index) than reducing saturated fat.
           Secondary outcomes include calorie intake, micro- and macronutrients at baseline,
           physical activity, and observe changes at 3- and 6-months.

        3. Adherence. We will examine adherence to the treatment protocol so that appropriate
           adjustments to the intervention can be made, if necessary, to enhance adherence in the
           larger randomized clinical trial.

        4. Data for sample size estimation. We will document means and standard deviations on
           measures so that sample size can be estimated for the larger randomized clinical trial.
    

Intervention name(s): High Fiber Diet; low saturated fat diet; Combination diet
Intervention type(s): Behavioral; Behavioral; Behavioral
Intervention description(s): high fiber diet (≥30 grams of total fiber per day); reduction of calories to -500 from resting metabolic rate (RMR), not less than 1200 kcal per day.; low saturated fat diet (≤7% of total calories); -500 calories from RMR, not less than 1200 kcal/day.; combination low saturated fat high fiber diet, with calorie restriction as specified.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Nutrition; Dietary Quality; Weight loss