Whole Grains, Gastric Emptying and Glycemic Response

Study Overview
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Brief Summary
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Whole grains have been associated with controlled glycemic response and increased satiety compared to refined grains. However, the properties of whole grains which are responsible for these purported improved health outcomes are still unclear. The current study investigated the extent of whole grains' low glycemic property when food properties are controlled, and how this relates to gastric emptying rate and glycemic response.

Detailed Description
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It is generally assumed that whole grain foods confer a health benefit in regards to moderated glycemia and increased satiety compared to foods made from refined grains. However, the extent of whole grains' low glycemic property may be limited by certain factors. For example, physical properties such as viscosity or particle size and differing starch digestion rates of whole grain foods may strongly influence glycemic response and gastric emptying rate. In this study, whole and refined grain wheat porridges were prepared from materials originating from the same milling source, with matched pairs for viscosity, starch and dietary fiber contents, and particle size. Subjects consumed wheat porridges containing 13C-labeled octanoic acid for assessment of gastric emptying rate, and they wore a continuous glucose monitor for measuring postprandial glucose levels. The purpose of this research was to test the hypothesis that the purported moderated glycemic response and slow gastric emptying rate are dependent on how these foods are processed. This work highlights the need to consider specific properties of whole grain foods for desired health outcomes in order to optimize the design of whole grain-based foods.

Official Title
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Glycemic Response of Whole Grain Wheat Meals

Conditions
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Obesity, Diabetes Mellitus, Type 2, Appetitive Behavior

Intervention / Treatment
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* Other: Cracked whole wheat porridge
* Other: Semolina wheat porridge
* Other: Whole wheat flour porridge
* Other: Refined wheat flour porridge
* Other: Refined wheat flour porridge,fine bran
* Other: Refined wheat flour porridge,coarse bran


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged between 18-50 years old Healthy, normal BMI (18.5 kg/m² <BMI < 25 kg/m²) Be free of any gastrointestinal diseases, diabetes, cardiovascular diseases Be free of any wheat allergies and gluten intolerances or sensitivities Not be pregnant or nursing Exclusion Criteria: No medical problems No medication Pregnant or nursing

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cracked whole wheat porridge<br>Large particle whole wheat porridge | Other: Cracked whole wheat porridge<br>* Large particle whole wheat porridge was tested for gastric emptying rate, glycemic response and appetitive response.<br>|
| Experimental: Semolina wheat porridge<br>Large particle refined wheat porridge | Other: Semolina wheat porridge<br>* Large particle refined wheat porridge was tested for gastric emptying rate, glycemic response and appetitive response.<br>|
| Experimental: Whole wheat flour porridge<br>Small particle whole wheat porridge | Other: Whole wheat flour porridge<br>* Small particle whole wheat porridge was tested for gastric emptying rate, glycemic response and appetitive response.<br>|
| Experimental: Refined wheat flour porridge<br>Small particle refined wheat porridge | Other: Refined wheat flour porridge<br>* Small particle refined wheat porridge was tested for gastric emptying rate, glycemic response and appetitive response.<br>|
| Experimental: Refined wheat flour porridge,fine bran<br>Small particle refined wheat porridge with small particle bran | Other: Refined wheat flour porridge,fine bran<br>* Small particle refined wheat porridge with small particle bran was tested for gastric emptying rate, glycemic response and appetitive response.<br>|
| Experimental: Refined wheat flour porridge,coarse bran<br>Small particle refined wheat porridge with large particle bran | Other: Refined wheat flour porridge,coarse bran<br>* Small particle refined wheat porridge with large particle bran was tested for gastric emptying rate, glycemic response and appetitive response.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gastric emptying | Breath test was performed using 13C-octanoic acid mixed into test meals | Acute study, 4 hours measurement after consumption of test food | 
| Glycemic response | Blood glucose was measured using a continuous glucose monitor | Acute study, 4 hours measurement after consumption of test food | 
| Appetitive behavior | Hunger and fullness scores using a 10 cm scale (0 = weakest feeling of hunger or fullness and 10 = highest feeling of hunger or fullness) will be taken after each meal. | Acute study, 4 hours measurement after consumption of test food. |