Whole Grains, Gastric Emptying and Glycemic Response

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.

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.

Large particle whole wheat porridge was tested for gastric emptying rate, glycemic response and appetitive response.

Large particle refined wheat porridge was tested for gastric emptying rate, glycemic response and appetitive response.

Small particle whole wheat porridge was tested for gastric emptying rate, glycemic response and appetitive response.

Small particle refined wheat porridge was tested for gastric emptying rate, glycemic response and appetitive response.

Small particle refined wheat porridge with small particle bran was tested for gastric emptying rate, glycemic response and appetitive response.

Small particle refined wheat porridge with large particle bran was tested for gastric emptying rate, glycemic response and appetitive response.

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.

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

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