Effect of a Low-Carbohydrate and High-Carbohydrate, High-Fiber Diet on Insulin Sensitivity and Risk Markers for Cardiovascular Disease in Men and Women With the Metabolic Syndrome
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Metabolic Syndrome X
- Sponsor
- University of Virginia
- Enrollment
- 24
- Locations
- 1
- Primary Endpoint
- insulin sensitivity
- Last Updated
- 17 years ago
Overview
Brief Summary
The purpose of this study is to compare the effects of a low-carbohydrate diet and a high-carbohydrate, high-fiber diet, on insulin sensitivity and blood chemicals considered risk markers for heart disease, in persons with the metabolic syndrome.
Our primary hypothesis is that the ad libitum high-carbohydrate, high-fiber diet will significantly improve insulin sensitivity, whereas the ad libitum low-carbohydrate, low-fiber diet will not.
Detailed Description
Low-carbohydrate eating is becoming perceived as more than just a weight loss diet, but rather a means to improve health. Several studies have been published suggesting that low-carbohydrate diets may be preferable to low-fat diets for weight loss and in terms of some health markers. On the other hand, considerable evidence suggests that low-carbohydrate diets, high in fat, are associated with a number of adverse health outcomes. The health benefits of high-carbohydrate, high-fiber diets have also been demonstrated. This study is designed to assess the differences between the two different dietary strategies in terms of a number of health outcomes. Participants will consume, in random order, a non-calorie-restricted low-carbohydrate and a non-calorie-restricted high-carbohydrate, high-fiber diet for one month, with a 4-6 week washout period in between.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Subjects must meet the criteria of the metabolic syndrome, which is defined as having three or more of the following:
- •Waist circumference: \>94 cm for males; \>80 cm for females
- •Blood Pressure: \>130/85 mmHg
- •HDL-Chol (mg/dl): \<50 women; \<40 men)
- •Triglycerides (mg/dl): \>150
- •Glucose (mg/dl): \>100
- •Subjects must meet age requirement
- •Subjects must be nonsmokers
- •Subjects must be willing to provide written consent
- •Subjects must be willing to pick-up up meals at the GCRC and return uneaten food
Exclusion Criteria
- •Does not meet the criteria for the metabolic syndrome
- •Does not meet age requirement
- •Food allergies
- •Unwillingness to provide written consent
- •Personal history of cardiovascular disease, including prior myocardial infarction, angioplasty, or bypass surgery
- •Known cardiovascular or metabolic diseases (e.g., diabetes)
- •Currently using medications to control blood pressure, lipids, or glucose
- •Currently on a diet or has attempted weight loss by dieting during the past 3 months
- •Currently taking nutritional supplements other than a daily multivitamin
- •Currently exercising more than the equivalent of 30 minutes/day of moderate-intensity physical activity
Outcomes
Primary Outcomes
insulin sensitivity
Time Frame: before and after one month on each diet
Secondary Outcomes
- Total and LDL-cholesterol(before and after one month on each diet)
- C-reactive protein(before and after one month on each diet)
- Homocysteine(before and after one month on each diet)
- Fibrinogen(before and after one month on each diet)
- Cytokines IL-1, IL-2, IL-6 and TNF-alpha(before and after one month on each diet)
- Leukocyte adhesion molecules(before and after one month on each diet)
- Flow-mediated dilation(before and after one month on each diet)