Cardiovascular Disease, Metabolic Syndrome, Obesity
Conditions
Keywords
nutrition, popular diets, weight loss, lifestyle, counseling
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.
Interventions
BEHAVIORALAtkins Diet
Dietary counseling for 1 year
BEHAVIORALZone Diet
Dietary counseling for 1 year
BEHAVIORALWeight Watchers Diet
Dietary counseling for 1 year
BEHAVIORALOrnish Diet
Dietary counseling for 1 year
Sponsors
Tufts Medical Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Weight Loss | 1 year | Change from baseline body weight at 1 year, measured in kilograms |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 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 |
| Total Cholesterol | 1 year | Change in total cholesterol from baseline 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 |
| Glucose | 1 year | Change from baseline glucose at 1 year, measured in mg/dL |
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Atkins Diet Atkins Diet (dietary counseling)
Atkins Diet: Dietary counseling for 1 year | 40 |
| Zone Diet Zone Diet (dietary counseling)
Zone Diet: Dietary counseling for 1 year | 40 |
| Weight Watchers Diet Weight Watchers Diet (dietary counseling)
Weight Watchers Diet: Dietary counseling for 1 year | 40 |
| Ornish Diet Ornish Diet (dietary counseling)
Ornish Diet: Dietary counseling for 1 year | 40 |
| Total | 160 |
Baseline characteristics
| Characteristic | Atkins Diet | Zone Diet | Weight Watchers Diet | Ornish Diet | Total |
|---|---|---|---|---|---|
| Age, Continuous | 47 years STANDARD_DEVIATION 12 | 51 years STANDARD_DEVIATION 9 | 49 years STANDARD_DEVIATION 10 | 49 years STANDARD_DEVIATION 12 | 49 years STANDARD_DEVIATION 11 |
| Region of Enrollment United States | 40 participants | 40 participants | 40 participants | 40 participants | 160 participants |
| Sex: Female, Male Female | 21 Participants | 20 Participants | 23 Participants | 17 Participants | 81 Participants |
| Sex: Female, Male Male | 19 Participants | 20 Participants | 17 Participants | 23 Participants | 79 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — | — / — |
| other Total, other adverse events | 0 / 40 | 0 / 40 | 0 / 40 | 0 / 40 |
| serious Total, serious adverse events | 0 / 40 | 0 / 40 | 0 / 40 | 0 / 40 |
Outcome results
Primary
Weight Loss
Change from baseline body weight at 1 year, measured in kilograms
Time frame: 1 year
Population: Intent-to-treat analysis. Missing data were replaced with baseline values.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Atkins Diet | Weight Loss | -2.1 kg | Standard Deviation 4.8 |
| Zone Diet | Weight Loss | -3.2 kg | Standard Deviation 6 |
| Weight Watchers Diet | Weight Loss | -3.0 kg | Standard Deviation 4.9 |
| Ornish Diet | Weight Loss | -3.3 kg | Standard Deviation 7.3 |
Secondary
C-reactive Protein
Change from baseline high-sensitivity CRP at 1 year, measured in mg/L
Time frame: 1 year
Population: Intent-to-treat analysis. Missing data were replaced with baseline values.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Atkins Diet | C-reactive Protein | -0.70 mg/L | Standard Deviation 2.1 |
| Zone Diet | C-reactive Protein | -0.58 mg/L | Standard Deviation 2.1 |
| Weight Watchers Diet | C-reactive Protein | -0.58 mg/L | Standard Deviation 1.3 |
| Ornish Diet | C-reactive Protein | -0.88 mg/L | Standard Deviation 2.4 |
Secondary
Glucose
Change from baseline glucose at 1 year, measured in mg/dL
Time frame: 1 year
Population: Intent-to-treat analysis. Missing data were replaced with baseline values.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Atkins Diet | Glucose | 1.4 mg/dL | Standard Deviation 30 |
| Zone Diet | Glucose | -4.2 mg/dL | Standard Deviation 18 |
| Weight Watchers Diet | Glucose | -4.7 mg/dL | Standard Deviation 19 |
| Ornish Diet | Glucose | -4.1 mg/dL | Standard Deviation 30 |
Secondary
HDL Cholesterol
Change from baseline HDL cholesterol at 1 year, measured in mg/dL
Time frame: 1 year
Population: Intent-to-treat analysis. Missing data were replaced with baseline values.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Atkins Diet | HDL Cholesterol | 3.4 mg/dL | Standard Deviation 7.1 |
| Zone Diet | HDL Cholesterol | 3.3 mg/dL | Standard Deviation 10.3 |
| Weight Watchers Diet | HDL Cholesterol | 3.4 mg/dL | Standard Deviation 9.9 |
| Ornish Diet | HDL Cholesterol | -0.5 mg/dL | Standard Deviation 6.5 |
Secondary
Insulin
Change from baseline insulin at 1 year, measured in microIU/mL
Time frame: 1 year
Population: Intent-to-treat analysis. Missing data were replaced with baseline values
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Atkins Diet | Insulin | -1.2 microIU/ml | Standard Deviation 6.7 |
| Zone Diet | Insulin | -5.4 microIU/ml | Standard Deviation 14 |
| Weight Watchers Diet | Insulin | -2.6 microIU/ml | Standard Deviation 6.1 |
| Ornish Diet | Insulin | -3.0 microIU/ml | Standard Deviation 6.3 |
Secondary
LDL Cholesterol
Change from baseline LDL cholesterol at 1 year, measured in mg/dL
Time frame: 1 year
Population: Intent-to-treat analysis. Missing data were replaced with baseline values
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Atkins Diet | LDL Cholesterol | -7.1 mg/dL | Standard Deviation 24 |
| Zone Diet | LDL Cholesterol | -11.8 mg/dL | Standard Deviation 34 |
| Weight Watchers Diet | LDL Cholesterol | -9.3 mg/dL | Standard Deviation 27 |
| Ornish Diet | LDL Cholesterol | -12.6 mg/dL | Standard Deviation 19 |
Secondary
Total Cholesterol
Change in total cholesterol from baseline at 1 year, measured in mg/dL
Time frame: 1 year
Population: Intent-to-treat analysis. Missing data were replaced with baseline data.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Atkins Diet | Total Cholesterol | -4.3 mg/dL | Standard Deviation 23 |
| Zone Diet | Total Cholesterol | -10.1 mg/dL | Standard Deviation 35 |
| Weight Watchers Diet | Total Cholesterol | -8.2 mg/dL | Standard Deviation 24 |
| Ornish Diet | Total Cholesterol | -10.8 mg/dL | Standard Deviation 21 |
Secondary
Triglycerides
Change from baseline triglycerides at 1 year, measured in mg/dL
Time frame: 1 year
Population: Intent-to-treat analysis. Missing data were replaced with baseline values
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Atkins Diet | Triglycerides | -1.2 mg/dL | Standard Deviation 84 |
| Zone Diet | Triglycerides | 2.5 mg/dL | Standard Deviation 147 |
| Weight Watchers Diet | Triglycerides | -12.7 mg/dL | Standard Deviation 61 |
| Ornish Diet | Triglycerides | 5.6 mg/dL | Standard Deviation 36 |