Comparison of the Postprandial Glycemic and Insulinemic Response After a Fibersym Containing Cookie With a Control
Condition: Postprandial Hyperglycemia
MeSH terms: Hyperglycemia
Study type: Interventional

Summary: 
      Fibersym® is a RS4-type resistant modified wheat starch in which over 85% of the total starch
      is resistant starch as measured by AOAC method 991.43. It is meant to be consumed on a
      regular basis and doses up to 33g/day can be tolerated. The effect of a Fibersym-containing
      meal on postprandial glucose and insulin levels when compared to a control meal, where both
      meals contain the same amount of available carbohydrate, is not known. This study therefore
      investigated the acute effect of a Fibersym cookie and a control cookie matched for available
      carbohydrate after a 3-day habituation period.
    

Detailed description: 
      The study used a double-blind, randomized, cross-over design.

      Visit 1: Participants willing to be considered were invited to come to the research centre to
      have the study procedures explained to them and be given a copy of the consent form which
      they may either sign then, take away to sign at a later date, or decline to participate.
      Participants were encouraged to ask any questions they may have and not to sign the consent
      form until all of their questions have been answered to their satisfaction. Those who
      consented to participate came to the research centre for a pre-selection visit when subject
      eligibility will be determined. A number of parameters were assessed including blood
      pressure, weight, height, BMI, and brief medical history.

      Visit 2-3: Eligible subjects were randomized using an online randomization calculator.
      Eligible subjects were studied on 2 separate days over a period of 6 weeks or less. Prior to
      each test meal, they were provided with enough cookies to consume 3 times/day over 3 days and
      instructed to start consuming the cookies 3 days before their visit. They were also provided
      with a calorie appropriate, standard frozen dinner to be consumed on the evening before their
      test meal. The interval between successive tests was no less than 6 days and no more than 4
      weeks. On each test day, participants came to GI Labs in the morning after a 10-12 h
      overnight fast (except for water). Participants were asked to maintain stable dietary and
      activity habits throughout their participation and to refrain from drinking alcohol and from
      unusual levels of food intake or physical activity for 24 h before each test. Before the
      start of the test meal, subjects were asked whether they consumed the provided cookies over
      the last 3 days as instructed and the standard dinner the evening before. Subjects were asked
      to complete a 3- day record of supplement consumption and whether they consumed the standard
      evening meal, in addition to a 3-day symptom diary before each test visit. If any subject was
      not feeling well or had not complied with the preceding experimental conditions, the test was
      not carried out and was rescheduled for another day. On each test day, two fasting
      fingerprick blood samples were collected at -5 min and 0 min. Each sample consisted of 2
      vials, one for glucose analysis and one for insulin analysis (4-8 drops of blood each).
      Questionnaires to record satiety and GI symptoms were administered. Participants were then
      given the test food together with 250 ml of water and instructed to consume them over 15
      minutes. Additional blood samples were collected 15, 30, 45, 60, 90 and 120 min after the
      start of the test meal. Satiety questionnaires were administered at the same time intervals.
      GI symptom questionnaires were filled out at 2 h in addition to fasting.

      Test Foods:

      The sugar snap cookie formula (Control) was obtained from the American Institute of Baking
      (AIB) International (Manhattan, KS). Fibersym RW (Appendix 1) was added as an extra portion
      to the Control Cookie recipe, amounts were adjusted so that both the control and Fibersym
      cookie portions contained the same amount of available carbohydrate (ingredients are listed
      in appendix 1). Both cookies were baked at the facilities of AIB. The macronutrient
      composition of baked cookies was determined by an independent laboratory and the final
      weights of the cookies fed were adjusted accordingly.

      For the test breakfasts during the postprandial visit, the subject consumed approximately 3
      cookies containing 40 g available carbohydrates, the weight of Control Cookies per meal was
      78.1g whereas the weight of Fibersym Cookies per meal was 97.8 g (delivering 21 g of fiber
      from Fibersym and 2.1g from the flour) (Table 1). Both test meals were consumed with 250 ml
      of water.

      During the 3-day pre-feeding period, subjects consumed 108.9g cookies (approx. 3.5) of
      Control Cookies per day and 136.2 g of Fibersym Cookies (approx. 4) per day (delivering 29 g
      fiber from Fibersym/day). The cookies were consumed during the 3 meals (breakfast, lunch and
      dinner). Both the control and Fibersym cookies contributed 50g available carbohydrate per
      day. The product was re-packaged by a GI Labs staff member not involved in the clinical
      trial. Product label displayed the subject number, subject initials, product ID, ingredients
      statement, GIL repacked date, expiration date, researcher name and telephone number,
      investigational use statement, and allergy warnings (if needed). Study Product Intake Logs
      were completed upon dispensation of study product to each subject. After the data had been
      entered, checked for errors and the database locked, the code was broken, #149 corresponded
      to the control cookie while 394 corresponded to the Fibersym cookie.

      All subjects were asked to consume a standard evening meal provided by GI Labs and consisted
      of a frozen dinner.
    

Intervention name(s): Fibersym; Control cookie
Intervention type(s): Other; Other
Intervention description(s): RS4-type resistant modified wheat starch; control cookie
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: double blind, controlled, cross-over clinical trial
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Other