Effectiveness of Four Popular Diet Strategies for Weight Loss and Cardiac Risk Reduction

Study Overview
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Brief Summary
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A single-center randomized trial at an academic medical center in Boston, Mass, of overweight or obese adults with known hypertension, dyslipidemia, or fasting hyperglycemia. Participants were enrolled starting July 18, 2000, and randomized to 4 popular diet groups until January 24, 2002.

Detailed Description
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Objective: To assess adherence rates and the effectiveness of 4 popular diets (Atkins, Zone, Weight Watchers, and Ornish) for weight loss and cardiac risk factor reduction. Design, Setting, and Participants: A single-center randomized trial at an academic medical center in Boston, Mass, of overweight or obese adults with known hypertension, dyslipidemia, or fasting hyperglycemia. Participants were enrolled starting July 18, 2000, and randomized to 4 popular diet groups until January 24, 2002. Intervention: A total of 160 participants were randomly assigned to either Atkins (carbohydrate restriction, n=40), Zone (macronutrient balance, n=40), Weight Watchers (calorie restriction, n=40), or Ornish (fat restriction, n=40) diet groups. After 2 months of maximum effort, participants selected their own levels of dietary adherence. Main Outcome Measures: One-year changes in baseline weight and cardiac risk factors, and self-selected dietary adherence rates per self-report. Outcome measures included body weight, total cholesterol, LDL-C, HDL-C, triglycerides, hsCRP, insulin, glucose.

Official Title
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Effectiveness of Four Dietary Treatment Strategies for Metabolic Syndrome: a Prospective Randomized Trial

Conditions
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Obesity, Cardiovascular Disease, Metabolic Syndrome

Intervention / Treatment
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* Behavioral: Atkins Diet
* Behavioral: Zone Diet
* Behavioral: Weight Watchers Diet
* Behavioral: Ornish Diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI 27-42; At least one metabolic cardiac risk factor Exclusion Criteria: Age under 18 years; Insulin therapy; Unstable chronic illness; Unwilling to follow dietary advice

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Atkins Diet<br>Atkins Diet (dietary counseling) | Behavioral: Atkins Diet<br>* Dietary counseling for 1 year<br>|
| Active Comparator: Zone Diet<br>Zone Diet (dietary counseling) | Behavioral: Zone Diet<br>* Dietary counseling for 1 year<br>|
| Active Comparator: Weight Watchers Diet<br>Weight Watchers Diet (dietary counseling) | Behavioral: Weight Watchers Diet<br>* Dietary counseling for 1 year<br>|
| Active Comparator: Ornish Diet<br>Ornish Diet (dietary counseling) | Behavioral: Ornish Diet<br>* Dietary counseling for 1 year<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Weight Loss | Change from baseline body weight at 1 year, measured in kilograms | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total Cholesterol | Change in total cholesterol from baseline at 1 year, measured in mg/dL | 1 year | 
| LDL Cholesterol | Change from baseline LDL cholesterol at 1 year, measured in mg/dL | 1 year | 
| HDL Cholesterol | Change from baseline HDL cholesterol at 1 year, measured in mg/dL | 1 year | 
| Triglycerides | Change from baseline triglycerides at 1 year, measured in mg/dL | 1 year | 
| Glucose | Change from baseline glucose at 1 year, measured in mg/dL | 1 year | 
| Insulin | Change from baseline insulin at 1 year, measured in microIU/mL | 1 year | 
| C-reactive Protein | Change from baseline high-sensitivity CRP at 1 year, measured in mg/L | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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nutrition, popular diets, weight loss, lifestyle, counseling