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

Not Applicable

Completed

• Conditions: Obesity; Cardiovascular Disease; Metabolic Syndrome
• Interventions: Behavioral: Atkins Diet; Behavioral: Ornish Diet; Behavioral: Zone Diet; Behavioral: Weight Watchers Diet

• Registration Number: NCT02454127
• Lead Sponsor: Tufts Medical Center

Brief Summary

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

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.

Study Timeline

• Study Start: 2000-07
• Primary Completion: 2003-01
• Study Completion: 2004-01
• Study First Submitted: 2015-05-20
• Study First Submitted QC: 2015-05-26
• Study First Posted: 2015-05-27
• Results First Submitted: 2015-05-28
• Status Verified: 2016-09
• Results First Submitted QC: 2016-09-13
• Last Update Submitted: 2016-09-13
• Results First Posted: 2016-10-31
• Last Update Posted: 2016-10-31

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 160

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Atkins Diet	Atkins Diet	Atkins Diet (dietary counseling)
Ornish Diet	Ornish Diet	Ornish Diet (dietary counseling)
Zone Diet	Zone Diet	Zone Diet (dietary counseling)
Weight Watchers Diet	Weight Watchers Diet	Weight Watchers Diet (dietary counseling)

Primary Outcome Measures

Name	Time	Method
Weight Loss	1 year	Change from baseline body weight at 1 year, measured in kilograms

Secondary Outcome Measures

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