Comparison of the Atkins, Ornish, Weight Watchers, and Zone Diets for Weight Loss and Heart Disease Risk Reduction: A Randomized Trial | Cardiology | JAMA | JAMA Network
[Skip to Navigation]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address Please contact the publisher to request reinstatement.
Freedman MR, King J, Kennedy E. Popular diets: a scientific review.  Obes Res. 2001;9:(suppl 1)  1S-40S11374180Google ScholarCrossref
2. online book seller. Available at: Accessed December 2, 2004
Anderson JW, Konz EC, Jenkins DJ. Health advantages and disadvantages of weight-reducing diets: a computer analysis and critical review.  J Am Coll Nutr. 2000;19:578-59011022871Google ScholarCrossref
St Jeor ST, Howard BV, Prewitt TE, Bovee V, Bazzarre T, Eckel RH. Dietary protein and weight reduction: a statement for healthcare professionals from the Nutrition Committee of the Council on Nutrition, Physical Activity, and Metabolism of the American Heart Association.  Circulation. 2001;104:1869-187411591629Google ScholarCrossref
Bonow RO, Eckel RH. Diet, obesity, and cardiovascular risk.  N Engl J Med. 2003;348:2057-205812761363Google ScholarCrossref
Pagano-Therrien J, Katz DL. The low-down on low-carbohydrate diets.  Nurse Pract. 2003;28:5, 1412800688Google ScholarCrossref
Cheuvront SN. The Zone Diet phenomenon: a closer look at the science behind the claims.  J Am Coll Nutr. 2003;22:9-1712569110Google ScholarCrossref
Riley RE. Popular weight loss diets: health and exercise implications.  Clin Sports Med. 1999;18:691-70110410849Google ScholarCrossref
Lowe MR, Miller-Kovach K, Frye N, Phelan S. An initial evaluation of a commercial weight loss program: short-term effects on weight, eating behavior, and mood.  Obes Res. 1999;7:51-5910023730Google ScholarCrossref
Atkins R. Dr. Atkins' New Diet Revolution. New York, NY: Avon Books; 1998
Sears B. The Zone: A Dietary Road Map. New York, NY: HarperCollins Publishers; 1995
Ornish D. Every Day Cooking With Dean Ornish. New York, NY: HarperCollins Publishers; 1997
Flegal KM, Carroll MD, Ogden CL, Johnson CL. Prevalence and trends in obesity among US adults, 1999-2000.  JAMA. 2002;288:1723-172712365955Google ScholarCrossref
Blackburn GL, Phillips JC, Morreale S. Physician's guide to popular low-carbohydrate weight-loss diets.  Cleve Clin J Med. 2001;68:761, 765-766, 768-769, 773-76411563479Google ScholarCrossref
Eisenstein J, Roberts SB, Dallal G, Saltzman E. High-protein weight-loss diets: are they safe and do they work? a review of the experimental and epidemiologic data.  Nutr Rev. 2002;60:189-20012144197Google ScholarCrossref
Kennedy ET, Bowman SA, Spence JT, Freedman M, King J. Popular diets: correlation to health, nutrition, and obesity.  J Am Diet Assoc. 2001;101:411-42011320946Google ScholarCrossref
Foster GD, Wyatt HR, Hill JO.  et al.  A randomized trial of a low-carbohydrate diet for obesity.  N Engl J Med. 2003;348:2082-209012761365Google ScholarCrossref
Jarvis M, McNaughton L, Seddon A, Thompson D. The acute 1-week effects of the Zone diet on body composition, blood lipid levels, and performance in recreational endurance athletes.  J Strength Cond Res. 2002;16:50-5711834107Google Scholar
Samaha FF, Iqbal N, Seshadri P.  et al.  A low-carbohydrate as compared with a low-fat diet in severe obesity.  N Engl J Med. 2003;348:2074-208112761364Google ScholarCrossref
Westman EC, Yancy WS, Edman JS, Tomlin KF, Perkins CE. Effect of 6-month adherence to a very low carbohydrate diet program.  Am J Med. 2002;113:30-3612106620Google ScholarCrossref
Sondike SB, Copperman N, Jacobson MS. Effects of a low-carbohydrate diet on weight loss and cardiovascular risk factor in overweight adolescents.  J Pediatr. 2003;142:253-25812640371Google ScholarCrossref
Yancy WS Jr, Olsen MK, Guyton JR, Bakst RP, Westman EC. A low-carbohydrate, ketogenic diet versus a low-fat diet to treat obesity and hyperlipidemia: a randomized, controlled trial.  Ann Intern Med. 2004;140:769-77715148063Google ScholarCrossref
Brehm BJ, Seeley RJ, Daniels SR, D'Alessio DA. A randomized trial comparing a very low carbohydrate diet and a calorie-restricted low fat diet on body weight and cardiovascular risk factors in healthy women.  J Clin Endocrinol Metab. 2003;88:1617-162312679447Google ScholarCrossref
Meckling KA, O'Sullivan C, Saari D. Comparison of a low-fat diet to a low-carbohydrate diet on weight loss, body composition, and risk factors for diabetes and cardiovascular disease in free-living, overweight men and women.  J Clin Endocrinol Metab. 2004;89:2717-272315181047Google ScholarCrossref
Stern L, Iqbal N, Seshadri P.  et al.  The effects of low-carbohydrate versus conventional weight loss diets in severely obese adults: one-year follow-up of a randomized trial.  Ann Intern Med. 2004;140:778-78515148064Google ScholarCrossref
 NIH policy and guidelines on the inclusion of women and minorities as subjects in clinical research—amended, October, 2001. Available at: Accessed December 2, 2004
Sears B. Zone Perfect Meals in Minutes. New York, NY: HarperCollins Publishers; 1997
Weight Watchers Publishing Group.  Weight Watchers New Complete Cookbook. New York, NY: Macmillin Press; 1998
Atkins R, Gare F. Dr. Atkins' New Diet Cookbook. New York, NY: M Evans and Co Inc; 1995
Crawford PB, Obarzanek E, Morrison J, Sabry ZI. Comparative advantage of 3-day food records over 24-hour recall and 5-day food frequency validated by observation of 9- and 10-year-old girls.  J Am Diet Assoc. 1994;94:626-6308195550Google ScholarCrossref
McNamara JR, Schaefer EJ. Automated enzymatic standardized lipid analyses for plasma and lipoprotein fractions.  Clin Chim Acta. 1987;166:1-83608193Google ScholarCrossref
Friedewald WT, Levy RI, Fredrickson DS. Estimation of the concentration of low-density lipoprotein cholesterol in plasma, without use of the preparative ultracentrifuge.  Clin Chem. 1972;18:499-5024337382Google Scholar
Hedley AA, Ogden CL, Johnson CL, Carroll MD, Curtin LR, Flegal KM. Prevalence of overweight and obesity among US children, adolescents, and adults, 1999-2002.  JAMA. 2004;291:2847-285015199035Google ScholarCrossref
Connor WE, Connor SL. Should a low-fat, high-carbohydrate diet be recommended for everyone? the case for a low-fat, high-carbohydrate diet.  N Engl J Med. 1997;337:562-563, 566-5679262503Google ScholarCrossref
Landry N, Bergeron N, Archer R.  et al.  Whole-body fat oxidation rate and plasma triacylglycerol concentrations in men consuming an ad libitum high-carbohydrate or low-carbohydrate diet.  Am J Clin Nutr. 2003;77:580-58612600846Google Scholar
Brand-Miller JC. Glycemic load and chronic disease.  Nutr Rev. 2003;61:S49-S5512828192Google ScholarCrossref
Brinton EA, Eisenberg S, Breslow JL. A low-fat diet decreases high density lipoprotein (HDL) cholesterol levels by decreasing HDL apolipoprotein transport rates.  J Clin Invest. 1990;85:144-1512104877Google ScholarCrossref
Katan MB, Grundy SM, Willett WC. Should a low-fat, high-carbohydrate diet be recommended for everyone? beyond low-fat diets.  N Engl J Med. 1997;337:563-5669262504Google Scholar
Heshka S, Anderson JW, Atkinson RL.  et al.  Weight loss with self-help compared with a structured commercial program: a randomized trial.  JAMA. 2003;289:1792-179812684357Google ScholarCrossref
Koertge J, Weidner G, Elliott-Eller M.  et al.  Improvement in medical risk factors and quality of life in women and men with coronary artery disease in the Multicenter Lifestyle Demonstration Project.  Am J Cardiol. 2003;91:1316-132212767423Google ScholarCrossref
Ware JH. Interpreting incomplete data in studies of diet and weight loss.  N Engl J Med. 2003;348:2136-213712761370Google ScholarCrossref
Original Contribution
January 5, 2005

Comparison of the Atkins, Ornish, Weight Watchers, and Zone Diets for Weight Loss and Heart Disease Risk Reduction: A Randomized Trial

Author Affiliations

Author Affiliations: Division of Endocrinology, Diabetes, and Metabolism (Drs Dansinger and Schaefer), and Institute for Clinical Research and Health Policy Studies (Drs Griffith and Selker), Tufts-New England Medical Center; and Lipid Metabolism Laboratory, Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging, Tufts University (Dr Schaefer and Ms Gleason), Boston, Mass.

JAMA. 2005;293(1):43-53. doi:10.1001/jama.293.1.43

Context 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.

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 (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 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.

Results 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 = .002), 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 completers. Each diet significantly reduced the low-density lipoprotein/high-density lipoprotein (HDL) cholesterol ratio by approximately 10% (all P<.05), with no significant effects on blood pressure or glucose at 1 year. Amount of weight loss was associated with self-reported dietary adherence level (r = 0.60; P<.001) 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).

Conclusions Each popular diet modestly reduced body weight and several cardiac risk factors at 1 year. Overall dietary adherence rates were low, although increased adherence was associated with greater weight loss and cardiac risk factor reductions for each diet group.