Adiposity, Impaired Glucose Tolerance, Insulin Sensitivity, Metabolic Disturbance
Conditions
Keywords
Metabolism, Feeding, Substrate Oxidation, Metabolic Flexibility, High Fat Diet, Insulin Sensitivity
Brief summary
The purpose of this study is to understand how the body's response after a meal is influenced by insulin and sugar in the blood. The primary question this study seeks to address is what is the effect of reduced insulin sensitivity on postprandial metabolic flexibility to an oral glucose tolerance test. We will recruit 50 adults (ages 20-45; 50% female) who are otherwise healthy (no known clinical diagnosis) into our non-randomized crossover trial to determine the effect of changes in insulin sensitivity on metabolic response to feeding. Insulin sensitivity will be decreased using a three-day high-fat diet (HFD) with extra calories. Whole-body metabolism will be measured during a standard 75-gram oral glucose tolerance test (OGTT). Metabolic response to feeding (e.g. OGTT) will be compared before and after the HFD and compared with the control diet to understand the effect of decreased insulin sensitivity on the metabolic response to feeding. The role of biological sex as a moderator of the effect of increased insulin resistance on postprandial metabolic flexibility will also be investigated
Interventions
BEHAVIORALHypercaloric, High Fat Diet
Participants will select meals from a list of sample breakfast, lunch, and dinner options from grocery stores. Typical intake will be estimated as 160-170% of resting metabolic rate, which will then be multiplied by 1.65 as the target calorie intake for the HFD. Target fat intake will be 65% of the HFD calorie target. To ensure participants will achieve the desired calorie and fat intake, they will also be provided with pre-made nutrient shakes and half-and-half. Participants will supplement their food intake with one to three shakes per day for each of the three days, depending on the fat and calorie content of the foods they select. They will be asked to add half-and-half equally between across the shakes.
Sponsors
George Washington University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Non-Randomized Crossover
Eligibility
Sex/Gender
ALL
Age
20 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Males or Females between the ages of 20 and 45 years * Body mass index (BMI) of 18.5-29.9 kg/m2 * Low risk for medical complications as determined by physical activity readiness questionnaire (PARQ). * Low risk for food insecurity via the Hunger Vital Sign screener
Exclusion criteria
* Currently taking any antioxidant supplementation, prescription non-steroidal anti- inflammatory drugs, antibiotics, steroids, probiotics, medications for management of cholesterol, diabetes, body weight/obesity, or are undergoing transgender hormone therapy. * Currently pregnant (verified by urine pregnancy test) * Any history of disordered eating (i.e., anorexia nervosa, bulimia nervosa, binge eating disorder, etc.) or high risk for disordered eating via validated questionnaire (SCOFF) * Any history of gastrointestinal diseases (i.e., gastroesophageal reflux disease, irritable bowel syndrome, Celiac disease, Crohn's disease, or lactose intolerance) * Allergies to wheat or gluten, milk, soy, tree nuts (e.g., almonds, walnuts, pecans), or peanuts. * Followed a ketogenic diet within the last three months * Instructed by a medical provided to avoid a high-fat diet due to cardiovascular disease risk. * Cardiorespiratory fitness (VO2max) greater than the 90th percentile for age and sex
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Postprandial Metabolic Flexibility | 3 Days | Mean difference respiratory exchange ratio during an oral glucose tolerance test following a high fat diet |
Countries
United States
Outcome results
None listed