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
试验速览
- 阶段
- 不适用
- 入组人数
- 24
- 试验地点
- 2
- 主要终点
- insulin sensitivity
研究概览
简要总结
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.
详细描述
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Single (Investigator)
入排标准
- 年龄范围
- 18 Years 至 64 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •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
- •Have no food allergies
- •Subjects must not be currently following any particular diet, and must not have intentionally lost weight by dieting during the previous 3 months
- •Subjects must not be taking nutritional supplements other than a daily multivitamin
- •Subjects must be willing to maintain current physical activity routine, which cannot exceed the equivalent of > 30 minutes per day of moderate-intensity activity
- •Blood hematocrit must be at least 40 for men and 36 for women.
排除标准
- •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
- •Currently on oral contraceptives
- •Hematocrit below 40 for men or below 36 for women
- •Baseline systolic blood pressure below 100 mmHg
结局指标
主要结局
insulin sensitivity
时间窗: before and after one month on each diet
次要结局
- 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)