Comparison of Two Different Diets on Health Outcomes

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00269646
Recruitment Status : Unknown
Verified February 2009 by University of Virginia.
Recruitment status was:  Active, not recruiting
First Posted : December 23, 2005
Last Update Posted : February 18, 2009
Information provided by:
University of Virginia

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.

Condition or disease Intervention/treatment Phase
Metabolic Syndrome X Behavioral: Low-carbohydrate and high-carbohydrate diets Not Applicable

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.

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 24 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single (Investigator)
Primary Purpose: Treatment
Official Title: 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
Study Start Date : November 2004
Actual Primary Completion Date : February 2008
Estimated Study Completion Date : August 2009

Resource links provided by the National Library of Medicine

Intervention Details:
  • Behavioral: Low-carbohydrate and high-carbohydrate diets
    Each subject will consume two different ad libitum diets, each for four weeks, with a 4-week washout period inbetween each diet.

Primary Outcome Measures :
  1. insulin sensitivity [ Time Frame: before and after one month on each diet ]

Secondary Outcome Measures :
  1. Total and LDL-cholesterol [ Time Frame: before and after one month on each diet ]
  2. C-reactive protein [ Time Frame: before and after one month on each diet ]
  3. Homocysteine [ Time Frame: before and after one month on each diet ]
  4. Fibrinogen [ Time Frame: before and after one month on each diet ]
  5. Cytokines IL-1, IL-2, IL-6 and TNF-alpha [ Time Frame: before and after one month on each diet ]
  6. Leukocyte adhesion molecules [ Time Frame: before and after one month on each diet ]
  7. Flow-mediated dilation [ Time Frame: before and after one month on each diet ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 64 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

1. 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 2. Subjects must meet age requirement 3. Subjects must be nonsmokers 4. Subjects must be willing to provide written consent 5. Subjects must be willing to pick-up up meals at the GCRC and return uneaten food 6. Have no food allergies 7. Subjects must not be currently following any particular diet, and must not have intentionally lost weight by dieting during the previous 3 months 8. Subjects must not be taking nutritional supplements other than a daily multivitamin 9. Subjects must be willing to maintain current physical activity routine, which cannot exceed the equivalent of > 30 minutes per day of moderate-intensity activity 10. Blood hematocrit must be at least 40 for men and 36 for women.

Exclusion Criteria:

1. Does not meet the criteria for the metabolic syndrome 2. Does not meet age requirement 3. Smoker 4. Pregnancy 5. Food allergies 6. Unwillingness to provide written consent 7. Personal history of cardiovascular disease, including prior myocardial infarction, angioplasty, or bypass surgery 8. Known cardiovascular or metabolic diseases (e.g., diabetes) 9. Currently using medications to control blood pressure, lipids, or glucose 10. Currently on a diet or has attempted weight loss by dieting during the past 3 months 11. Currently taking nutritional supplements other than a daily multivitamin 12. Currently exercising more than the equivalent of 30 minutes/day of moderate-intensity physical activity 13. Currently on oral contraceptives 14. Hematocrit below 40 for men or below 36 for women 15. Baseline systolic blood pressure below 100 mmHg

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00269646

United States, Virginia
University of Virginia General Clinical Research Center
Charlottesville, Virginia, United States, 22904
Sponsors and Collaborators
University of Virginia
Principal Investigator: Glenn A Gaesser, PhD University of Virginia

Responsible Party: Glenn Gaesser/Principal Investigator, University of Virginia Identifier: NCT00269646     History of Changes
Other Study ID Numbers: HIC11487
First Posted: December 23, 2005    Key Record Dates
Last Update Posted: February 18, 2009
Last Verified: February 2009

Keywords provided by University of Virginia:
Dietary fiber
Cardiovascular disease

Additional relevant MeSH terms:
Cardiovascular Diseases
Metabolic Syndrome X
Pathologic Processes
Insulin Resistance
Glucose Metabolism Disorders
Metabolic Diseases