Glycemic Response of Bean-and-rice Meals in Type 2 Diabetes Mellitus
Condition: Blood Glucose; Type 2 Diabetes Mellitus
MeSH terms: Diabetes Mellitus; Diabetes Mellitus, Type 2
Study type: Interventional
Phase: Phase 2

Summary: 
      The study uses a randomized, placebo-controlled experimental design consisting of 4 different
      test treatments matched on carbohydrate (CHO) content. The three beans are similar in their
      CHO content amount for ½ cup at ~20 grams CHO. Each of the bean varieties will be served in a
      ~½ cup serving size with ~ ½ cup of plain steamed white rice (30 grams CHO) for a total of 50
      grams of CHO per meal for each of the three test treatments. The 4th placebo or control
      treatment consists of ~ 7/8 cup of rice alone, an amount consistent with the CHO content of
      the test meals. Most diabetic meal plans recommend no more than 45-60 grams of CHO per meal.
      Fifty grams of CHO is a standard amount for glycemic response testing in general.

      The investigators hypotheses were:

        -  The test meals containing the three bean types in combination with white rice will
           decrease the participants' glycemic response when eaten as part of a meal.

        -  The reduction in post-prandial glycemia will not differ between bean types in the
           elicited responses among individuals with type 2 diabetes.
    

Detailed description: 
      The 4 test treatments will be administered randomly on a different morning, at least one week
      apart. Participants will be required to consume the entire test treatment meal in 7 minutes
      while being observed. All test foods will be purchased from local markets. Capillary blood
      samples will be collected (~50µl) at time 0 (fasting) and at 30, 60, 90, 120 and 180 minutes
      post-treatment (timing of the post-treatment blood draws started at time 0 [post-treatment],
      which is when the participant finishes consuming the treatment meal). Venous blood draws for
      insulin assessment will also be acquired at fasting and then every hour for the three hour
      study period. Anthropometric measures such as weight, height and waist circumference will be
      collected at screening and at the start of each test day. Thirteen hours before testing,
      participants will eat a control meal to reduce variation in glycemic responses on test days
      due to varying dietary intakes. This control meal will be selected by each participant before
      the start of the study. They will be provided a gift card to the chain restaurant to use to
      purchase their own meal. Since subjects serve as their own controls, the meals must be
      identical before each test draw. Participants will complete 24 hour recall food records the
      morning of each test day to provide information related to dietary protocol compliance.
    

Intervention name(s): Whole cooked beans with rice meals
Intervention type(s): Other
Intervention description(s): Three types of bean-and-rice meals all equal to 50 grams available CHO. Control treatment was 50 grams available CHO in the form of white rice alone.
Other intervention name(s): Bush Brothers & Company brand canned beans
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: legumes; glycemic response; glucose; type 2 diabetes mellitus