Dietary Impact on Continuous Glucose Monitoring

Study Overview
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Brief Summary
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Cardiorespiratory fitness (CRF), also known as exercise capacity, is the capacity of respiratory and circulatory systems to supply oxygen to skeletal muscle during exercise for the generation of energy. Determinants of CRF include lung capacity, capillary density, cardiac output, hemoglobin concentration, and mitochondrial function. The research group studies how CRF is related to fuel utilization, yielding a mechanistic understanding of the association between lower CRF and worsening metabolic health via mitochondrial function. The objective of this study is to measure fuel utilization in response to habitual diet for one week in adolescents and young adults, ages 14-22 years (n=30). Fuel utilization will be estimated by glucose measures using a continuous glucose monitor (CGM). Habitual dietary intake will be collected via a mobile phone application (BiteAI, Inc) that uses artificial intelligence to extract nutrient information from food photographs. Participants will undergo two standard of care (SOC) meal tolerance tests at home - a glucose tolerance test and a Ensure® mixed meal tolerance test. CRF will be estimated by measuring maximum oxygen consumption (VO2 max) during a graded treadmill test. The hypothesis is that a higher VO2 max will be associated with increased fuel utilization, measured by lower glucose response to the SOC meal tolerance tests. The proposed study is described in the following aims: SPECIFIC AIM 1. Test for feasibility of completion of self-report dietary food records, completion of two at home meal tolerance tests that are standard of care for metabolic health screening, and completion of a seven-day continuous glucose monitor. SPECIFIC AIM 2. Identify nutrients and foods that are associated with an elevated glucose response. SPECIFIC AIM 3. Assess the influence of VO2 max on the glucose response to the SOC glucose tolerance test and Ensure® mixed meal tolerance test.

Official Title
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Impact of Dietary Intake on Continuous Glucose Patterns Considering Cardiorespiratory Fitness Levels.

Conditions
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Glucose Metabolism Disorders, Dietary Habits, Pediatric ALL, Adult ALL

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adolescents and young adults, ages 14-22 years Exclusion Criteria: Previous diagnosis of type 1 or 2 diabetes Previous diagnosis of hyperlipidemia or other metabolic disease Use of medications known to affect glucose metabolism (metformin, oral steroids, sulfonylureas, insulin). Allergies to milk. Inability to participant in the maximal exercise test on the treadmill. Individuals not having android or IOS phones Individuals who cannot speak and/or write in English.

Ages Eligible for Study
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Minimum Age: 14 Years
Maximum Age: 22 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of dietary records completed by each study participant | The researchers will measure dietary intake using a mobile phone application called BiteSnap. The goal is to have participants report >90% of their meals using mobile phone photos to extract nutrient information. | 7-10 days | 
| Number of days wearing the continuous glucose monitor | The researchers will measure the amount of time each participant wears the continuous glucose monitor. The goal is to have participants wear the monitor for >90% of the time in the study. | 7-10 days | 
| Completion of the at-home glucose tolerance test | Participants will be asked to drink a 75-gram glucose tolerance test. The researchers will measure the number of participants that self-reported drinking the shake at fasting. The goal will be 90% of participants self-report drinking the shake at fasting. | 7-10 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Identify nutrients associated with an elevated glucose response, measured by the continuous glucose monitor. | Participants will track the foods they eat while wearing the Dexcom continuous glucose monitors. Researchers will identify specific foods that are associated with increases in glucose response, considering associations across the group and associations within each individual. | 7-10 days | 
| Access the relationship between fitness levels and glucose response to standard of care meal tests. | Researchers will assess the association between fitness levels and glucose levels at 60 and 120 minutes after the at-home standard of care meal tests. Fitness levels are measured using a VO2 max test. | 7-10 days |