Effects of Stevia on Satiety and Eating Attitudes in Healthy, Overweight and Obese Adults
Condition: Obesity; Type 2 Diabetes
MeSH terms: Overweight
Study type: Interventional

Summary: 
      The purpose of this study is to test the effects that three different types of sweeteners
      have on food intake, hunger and satiety levels, as well as insulin and glucose measures. The
      study of whether food or beverages containing Stevia influence food intake to a greater
      extent than food or beverages sweetened with Aspartame or Sucrose. Also, examining whether
      taste preference and taste sensitivity influence food intake.
    

Detailed description: 
      Expected time in this study will be approximately 24 hours spread over the course of one
      initial screening visit and three test days during which you complete food tests at the
      Pennington Center.

      Screening visit (Duration is 3 hours)

        -  You will initially be asked to fill out psychological questionnaires to assess your
           eating habits, food cravings, and preference for foods (i.e., tea and crackers with
           cream cheese) that will be provided to you in this study.

        -  You will also be asked to complete two taste tests during this visit. The first taste
           test will be sodium chloride (table salt) followed by PROP (an extremely low dose of
           hyperthyroid medication) sodium chloride (table salt).

        -  You will be required to provide a blood sample (19 mL or 1.3 tablespoons) to check
           glucose and insulin levels.

        -  If you are selected to be a participant for this study, you will receive a brief medical
           evaluation during which you will be weighed, your height will be measured, and your
           pulse and blood pressure will be taken. You will be interviewed about your medical
           history and potential obstacles for completing the study. If you are female, a brief
           interview will be conducted to determine your menstrual cycle phase. Total length of
           time will be approximately three hours for the screening visit.

      First Food Test Day (Duration is 7- 9 hours. You'll arrive after having fasted for 12 hrs.)
      For females, all test meal days will be scheduled during their luteal phase. • Breakfast:
      During your first food test day, you will be asked to come to the Pennington Center at any
      time between the hours of 7:00 A.M. - 8:30 A.M. and consume a standard breakfast of Cheerios,
      milk, orange juice, toast, butter, and jelly. You will then be free to leave but will be
      asked to return 3.5 hours later. When your return, you will be sent to our inpatient unit for
      a blood draw, which will test your level of insulin and glucose (total of 25 mL or 1.67
      tablespoons). You will then be asked to rate your appetite on a computer using a visual
      analog scale (VAS). After completing these VAS ratings, you will be provided with an
      appetizer of 5 ounces of cold tea and 6 crackers with cream cheese. Both the tea and the
      cream cheese will be sweetened with one of the following sweeteners: Aspartame, Sucrose, or
      Stevia. After consuming this appetizer, you will be asked to complete another set of VAS
      ratings, which again ask you about your appetite, as well as the sweetness of the appetizer.
      Test times will be constant for all visits. Approximately twenty minutes after consuming this
      appetizer, your insulin and glucose levels will again be tested and you will complete another
      set of VAS ratings before your lunch meal. You will be required to consume breakfast at the
      same time for all three visits. For example, if you come at 7:00 A.M. on your first test day,
      you will be required to come in at 7:00 A.M. on your next two test days.

      • Lunch: After completing VAS ratings before lunch, you will be provided with a lunch
      consisting of sandwiches, chips, and cookies. Your lunch meal will be served approximately 4
      hours after your breakfast meal. Your eating behavior may be monitored by weight of the food
      consumed and/or by video camera/tape. You may eat as much or as little of the lunch as you
      wish.

      • After Lunch: After you finish your lunch meal, you will be asked to complete post meal VAS
      ratings. Your insulin and glucose will be measured on the three occasions after lunch: 30
      minutes after lunch, one hour after lunch, and two hours after lunch for a total of 5 blood
      draws (total of 25 mL or 1.67 tablespoons). You will also be asked to complete VAS ratings 30
      minutes after lunch, and every hour for the next four hours. You will spend the afternoon at
      the Pennington center to ensure that blood draws and VAS ratings occur at the appropriate
      time intervals. During the afternoon you will be free to read, do paperwork brought from home
      or work, or watch movies that will be provided to you by the Center.

      • Dinner:

      Four hours after the test lunch, you will be provided with another appetizer of 5 ounces of
      cold tea and crackers with cream cheese. Both the tea and the cream cheese will be sweetened
      with one of the following sweeteners: Stevia, sucrose, or Aspartame. You will complete VAS
      ratings before and after this appetizer, as well as before and after your dinner meal (4.5
      hours after lunch), during which you will be instructed to eat as much or as little of any of
      the items presented as you want. Your eating behavior may be monitored by weight of the food
      consumed and/or by video camera/tape. After you complete VAS questions after the evening
      meal, you will have fulfilled the requirements of the first food test day. However, you will
      be asked not to consume any food or caloric beverages for three hours following your dinner
      meal. You will be asked to report any adverse events from this day at this visit.

      Second Food Test Day (Duration is 7-9 hours. You'll arrive after having fasted for 12 hrs.) •
      On your second food test day, you will complete the same procedures and meal tests as you did
      during the first food test day. However, the type of sweetener used in your tea and crackers
      with cream cheese will differ from the type of sweetener you received on your first food test
      day. You will be asked to report any adverse events from this day, as well as previous
      visits, at this visit.

      Third Food Test Day (Duration is 7-9 hours. You'll arrive after having fasted for 12 hrs.)

      • On your third food test day, you will complete the same procedures and meal tests as you
      did during your two previous food test days. However, the type of sweetener used in your tea
      and crackers with cream cheese will differ from the type of sweetener you received on
      previous visits. You will also be asked to report any adverse events from this day, as well
      as previous visits, at this visit. We will also follow up by phone regarding adverse events
      following your third visit. Table 1 presents a schedule of the procedures that will take
      place at each of the study visits.
    

Intervention name(s): Aspartame; Sucrose; Stevia
Intervention type(s): Dietary Supplement; Dietary Supplement; Dietary Supplement
Intervention description(s): The morning breakfast after a 12-h fast and consumed a standard 469 kcal breakfast consisting of cereal, milk, toast with butter, and orange juice. Tea and crackers with cream cheese sweetened with stevia Whole Foods 365 Brand, aspartame equal sweetener, or sucrose participants consumed this preload 20 min before their test lunch and dinner meals. The Test lunch meal consisted of sandwiches, potato chips, and cookies, and the test dinner meal was a self-selected buffet-type meal (I.e., Macronutrient Self-Selection Paradigm) Geiselman et al,. 1998); The morning breakfast after a 12-h fast and consumed a standard 469 kcal breakfast consisting of cereal, milk, toast with butter, and orange juice. Tea and crackers with cream cheese sweetened with stevia Whole Foods 365 Brand, aspartame equal sweetener, or sucrose participants consumed this preload 20 min before their test lunch and dinner meals. The Test lunch meal consisted of sandwiches, potato chips, and cookies, and the test dinner meal was a self-selected buffet-type meal (I.e., Macronutrient Self-Selection Paradigm) Geiselman et al,. 1998); The morning breakfast after a 12-h fast and consumed a standard 469 kcal breakfast consisting of cereal, milk, toast with butter, and orange juice. Tea and crackers with cream cheese sweetened with stevia Whole Foods 365 Brand, aspartame equal sweetener, or sucrose participants consumed this preload 20 min before their test lunch and dinner meals. The Test lunch meal consisted of sandwiches, potato chips, and cookies, and the test dinner meal was a self-selected buffet-type meal (I.e., Macronutrient Self-Selection Paradigm) Geiselman et al,. 1998)
Other intervention name(s): equal sweetener
Allocation: Randomized
Intervention model: Single Group Assignment
Masking: Single (Participant)