This Study Assessed the Impact of Diet on Gastric Emptying Time and Metabolic Flexibility

Study Overview
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Brief Summary
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Consumption of slowly digestible carbohydrates can elicit higher satiety feeling compared to rapidly digestible carbohydrates, however not all individuals respond the same. The physiological mechanism that accounts for the satiety effect and the lack of consistency among subjects is not fully understood. The overall aim of this research is to determine if consumption of slow digestible carbohydrates can induce non-responding subjects (i.e., with rapid gastric emptying) to activate the ileal brake and delay rate of gastric emptying.

Detailed Description
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The purpose of this study is to understand how diet may affect carbohydrate digestion, gastric emptying time and overall health. The investigators will be recruiting 32 volunteers for this study. To be eligible for this study, you need to be between 18 and 50 years old, have a normal Body Mass Index, have a normal fasting blood glucose level, be free of any gastrointestinal diseases, diabetes, cardiovascular diseases, be free of wheat allergens, gluten intolerance or sensitivities, and allergy to millet, and not be pregnant or nursing. If you have any questions about the criteria, please ask the person consenting you. In this study, participants will consume two test meals at different times to assess gastric emptying times. Test meals will consist of either corn starch (30 g) or pregelatinized (DE-1 Maltodextrin) starch in applesauce (200 g) with xanthan gum (0.2 g) to equalize viscosity. Ingredients will be mixed immediately before consumption. For assessment of gastric emptying time, we will use a non-invasive 13C-labeled octanoic acid breath test. In our proposed procedure, 13C octanoic acid will be added to test meals, and breath samples will be taken before and after ingestion up to 4 hours. Breath samples will be collected every 15 minutes for first 2 hours and every 30 minutes for the next 2 hours. Participants will breathe into 300 mL bags and their content will be evaluated for [13C] using a 13CO2 Urea Breath Analyzer POCone (Otsuka Electronics Co, Ltd, Osaka, Japan) as measures of gastric emptying. We have used the labeled substrate and breath collection methods in our lab under previously approved IRB protocols at Purdue University (IRB Protocols #1102010450, #1104010761, #1209012595, #1405014904, and #1502015807, #1611018484, #1706019377. In addition, before, during, and after each session, subjects will also be asked to fill out a short questionnaire with questions regarding your hunger and fullness at those times. Test meals will be prepared in the university with trained personnel. All the ingredients will be purchased from approved food manufacturers. During testing days participants will be required to stay in the laboratory. Testing day sessions will last about 4 hours. The day prior testing, participants will be provided a standard meal but are not required to stay. For assessment of diet composition, three 24-hour dietary recalls will be used. Participants will be called on three different days. During these sessions, participants will be asked to recount quantity and types of foods consumed throughout the day, including two weekdays and one weekend day, to form a comprehensive picture of their dietary habits. Dietary data will be collected and stored using no personally identifiable information. The purpose of this study is to evaluate the continuous effect of slowly digestible carbohydrates consumption on gastric emptying and its potential health benefits.

Official Title
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Impact of Diet in Shaping Gastric Response and RER in Adults From Rural Africa and Urban USA

Conditions
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Obesity, Diabetes Mellitus, Type 2, Appetitive Behavior

Intervention / Treatment
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* Other: Raw Corn Starch
* Other: No Raw Corn Starch


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI 18.5 - 25.0 kg/m2 18 - 50 years Normal fasting blood glucose Exclusion Criteria: History of gastrointestinal disease Diabetes Pregnant and nursing women Wheat and/or gluten allergies or sensitivities Allergy to specific sources of slowly digestible carbohydrates

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: Sequential Assignment
Interventional Model Description: Repeated measures ANOVA, within factors.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Raw Corn Starch<br>Vehicle (apple sauce) will be spiked with 30 g of slowly digestible carbohydrate (raw corn starch) | Other: Raw Corn Starch<br>* Raw corn starch (30 g) will be added to 200 g of applesauce and served to participants, gastric emptying rate, and postprandial glucose will be measured.<br>|
| Placebo Comparator: No Raw Corn Starch<br>Vehicle (apple sauce) will not be spiked with 30 g of slowly digestible carbohydrate (raw corn starch) | Other: No Raw Corn Starch<br>* 200 g of applesauce will be consumed and gastric emptying rate, and postprandial glucose will be measured.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gastric emptying time | 13C octanoid acid labeled | Acute measurement of gastric emptying (4 hours post test meal consumption) | 
| Metabolic fuel utilization | Measured using RER with Lumen | Acute measures (2 hours post test meal consumption) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Self reported satiety scores | Hunger and fullness scores using a 10 cm scale (0=weakest feeling of hunger or fullness; 10=highest or strongest feeling of hunger or fullness) | Acute measurement of satiety or hunger scores (4 hours post test meal consumption) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Gastric emptying, Postprandial blood glucose