Digestive Properties of Carbohydrate-based Foods

Study Overview
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Brief Summary
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Gastric emptying rate, glycemic response, fermentation, and appetitive response are being assessed after consumption of traditional West African carbohydrate-based foods (pearl millet couscous, pearl millet thick porridge) and Western type carbohydrate-based foods (wheat couscous, white rice).

Detailed Description
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Anecdotal evidence suggests that couscous made from pearl millet (Pennisetum glaucum), hereby referred to as millet couscous, is highly satiating in populations living in the West African Sahel. Results from a previous human study conducted the investigators indicated that traditional West African foods made from pearl millet and sorghum (millet couscous, millet thick porridge, and sorghum thick porridge) exhibit markedly delayed rates of gastric emptying compared to Western foods (pasta, boiled potatoes, and white rice) in a population from Mali, Africa. The delayed gastric emptying rate of the thick porridges can be attributed at least partially to the impact of viscosity, while the cause of the delayed gastric emptying rate of the millet couscous remains unclear. The overall aim of this research is to determine why millet couscous exhibits a delayed rate of gastric emptying, while also assessing other digestive properties to gain a better understanding of the factors that could be contributing to this outcome. Therefore, gastric emptying rate, glycemic response, fermentation, and appetitive response are all being assessed for West African and Western foods in a population residing in the United States.

Official Title
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Investigating Digestive Properties of Carbohydrate-based Foods

Conditions
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Obesity, Diabetes Mellitus, Type 2, Appetitive Behavior

Intervention / Treatment
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* Other: Pearl millet couscous - made in Senegal
* Other: Pearl millet couscous - made in USA
* Other: Pearl millet thick porridge
* Other: Wheat couscous
* Other: White rice


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Normal body mass index (18.5 < BMI < 25 kg/m2) Normal fasting blood glucose Exclusion Criteria: Diabetes Allergy to millet Allergy or sensitivity/intolerance to gluten History of gastrointestinal disease 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: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Pearl millet couscous - made in Senegal<br>Steamed pearl millet couscous - commercially produced in Senegal | Other: Pearl millet couscous - made in Senegal<br>* Pearl millet couscous (made in Senegal) was tested for gastric emptying rate, glycemic response, fermentability, and appetitive response.<br>|
| Experimental: Pearl millet couscous - made in USA<br>Steamed pearl millet couscous - pearl millet obtained from Senegal but processed and prepared in USA | Other: Pearl millet couscous - made in USA<br>* Pearl millet couscous (made in USA) was tested for gastric emptying rate, glycemic response, fermentability, and appetitive response.<br>|
| Experimental: Pearl millet thick porridge<br>Thick porridge prepared according to traditional West African methods with pearl millet obtained from Senegal but processed and prepared in USA | Other: Pearl millet thick porridge<br>* Pearl millet thick porridge was tested for gastric emptying rate, glycemic response, fermentability, and appetitive response.<br>|
| Experimental: Wheat couscous<br>Steamed wheat couscous - wheat flour processed and prepared in USA | Other: Wheat couscous<br>* Wheat couscous was tested for gastric emptying rate, glycemic response, fermentability, and appetitive response.<br>|
| Active Comparator: White rice<br>White rice - medium-grain prepared using a rice cooker | Other: White rice<br>* White rice was tested as a comparator for gastric emptying rate, glycemic response, fermentability, and appetitive response.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gastric emptying rate | Breath test is being performed using 13C-octanoic acid mixed into test meals. | Acute study; 4 hours of measurement after consumption of test food | 
| Glycemic response | Blood glucose is being measured using continuous glucose monitors. | Acute study; 4 hours of measurement after consumption of test food | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Breath hydrogen (fermentability) | Breath samples are being collected at certain intervals for 4 hours after consumption of test food and analyzed for hydrogen levels using a breath analyzer. Breath hydrogen levels are indicative of a food's fermentability. | Acute study; 4 hours of measurement after consumption of test food | 
| Appetitive response | Hunger and fullness scores are being measured using a 10-cm scale (0 = weakest feeling of hunger or fullness and 10 = strongest feeling of hunger or fullness) after consumption of test food. Weaker feelings of hunger and stronger feelings of fullness are indicative of better outcomes. | Acute study; 4 hours of measurement after consumption of test food |