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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #184917
Title: COMPARISON OF THE ATKINS, ORNISH, WEIGHT WATCHERS AND ZONE DIETS FOR WEIGHT LOSS AND HEART DISEASE RISK REDUCTION

Author
item DANSINGER, MICHAEL - TUFTS-N.E. MEDICAL CTR
item GLEASON, JOI - TUFTS/HNRCA
item GRIFFITH, JOHN - TUFTS-N.E. MEDICAL CTR
item SELKER, HARRY - TUFTS-N.E. MEDICAL CTR
item SCHAEFER, ERNST - TUFTS/HNRCA

Submitted to: Journal of the American Medical Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/4/2004
Publication Date: 1/5/2005
Citation: Dansinger, M.L., Gleason, J.A., Griffith, J.L., Selker, H.P., Schaefer, E.J. 2005. Comparison of the Atkins, Ornish, Weight Watchers and Zone diets for weight loss and heart disease risk reduction. Journal of the American Medical Association. 293(1):43-53.

Interpretive Summary: Being overweight and obese is a major problem in America. Obesity predisposes to an increased risk for heart disease. Many diets have been advocated for weight loss. We evaluated the effectiveness of four popular diets over a one year period of time in promoting weight loss and heart disease risk reduction in 160 people who were either overweight or obese. These diets were the Atkins diet which promotes restriction of carbohydrates, the Ornish diet which promotes restriction of fat, the Weight Watchers Diet which promotes restriction of calories, and the Zone diet which promotes decreased portion size, increasing protein, and decreasing carbohydrate that raises blood sugar levels. Forty subjects were placed on each program by giving them the appropriate book and four classes on the diet, with evaluations at baseline, 2, 6, and 12 months. Drop outs were somewhat greater in the extreme diets (19 of 40 for Atkins and 20 of 40 for Ornish) than the less extreme diets (14 of 40 each for Weight Watchers and Zone). In the completers weight loss was 8.6 (Atkins), 14.5 (Ornish), 10.1 (Weight Watchers), and 10.8 pounds (Zone), respectively for these diets, and the best predictor of weight loss was self rated compliance. All diets promoted reduction in cardiovascular risk, especially in reducing the total cholesterol/HDL ratio. The overall data support the concept there various ways of restricting calories can promote weight loss.

Technical Abstract: The scarcity of data addressing the health effects of popular diets is an important public health concern, especially since patients and physicians are interested in using popular diets as individualized eating strategies for disease prevention. Our objective was to assess the effectiveness of 4 popular diets (Atkins, Ornish, Weight Watchers and Zone) for weight loss and cardiac risk factor reduction. The study was conducted at a single-center randomized trial at an academic medical center in Boston, MA. Participants were 160 overweight or obese (Body mass index mean=35, range , 27-42) adults aged 22 to 72 years with known hypertension, dyslipidemia or fasting hyperglycemia. Participants were enrolled starting July 18, 2000 and randomized to 4 popular diet groups until January, 2002. Participants were randomly assigned to either Atkins (carbohydrate restriction, n=40), Ornish (fat restriction, n=40), Weight Watchers (calorie restriction, n=40) or Zone (macronutrient balance, n=40) diet groups. After 2 months of maximum effort, participants selected their own level of dietary adherence. Main outcome measures were one-year changes in baseline weight and cardiac risk factors, and self-selected dietary adherence rates per self-report. Assuming no change from baseline for participants who discontinued the study, mean (SD) weight loss at 1 year was 2.1 (4.8) kg for Atkins, (21 [53%] of 40 participants completed, P=.009), 3.2 (6.0) kg for Zone (26 [65%] of 40 completed, P<.05), 3.0 (4.9) kg for Weight Watchers (26 [65%] of 40 completed, P<.001) and 3.3 (7.3) kg for Ornish (20 [50%] of 40 completed, P=.007). Greater effects were observed in study completer. Each diet significantly reduced the low-density lipoprotein/high-density lipoprotein (HDL) cholesterol ratio by approximately 1-% (all P<.05), with no significant effects of blood pressure or glucose at 1 year. Amount of weight loss was associated with self-reported dietary adherence level (r=0.60; P<.001)m but not with diet type (r=0.07; P=.40). For each diet, decreasing levels of total/HDL cholesterol, C-reactive protein, and insulin were significantly associated with weight loss (mean r=0.36, 0.37 and 0.39 respectively) with no significant difference between diets (P=.48, P=.57, P=.31, respectively). Each popular diet modestly reduced body weight and several cardiac risk factors at 1 year. Overall dietary adherence was associated with greater weight loss and cardiac risk factor reductions for each diet group.