1. Home>
2. Specialties>
3. Cardiology>
4. Summary and Comment

Pick a Diet, Then Stick to It

Diet adherence mattered much more than diet choice in a randomized comparison of four popular diets.

Which of the popular diets is best for weight loss and modification of heart-disease risk factors? To find out, researchers randomized 160 overweight people (mean age, 49; 51% women; mean BMI, 35) to follow one of four diets: low-fat (Ornish), low-carb (Atkins), low-glycemic-load (Zone), or portion- and calorie-restricted (Weight Watchers). All participants attended four diet classes over 8 weeks to improve adherence, with no specific interventions thereafter.

By 1 year, all diet groups had achieved only modest, albeit statistically significant, mean weight reduction (range, 2.1-3.3 kg), with no significant differences among the diets. In addition, benefits in LDL-to-HDL cholesterol ratio, triglyceride levels, and blood pressure were similar among the diets. Weight loss was significantly associated with improvements in total-to-HDL cholesterol ratio, C-reactive protein levels, and insulin levels, regardless of diet type.

The greatest weight-loss and risk-factor benefits were observed among study completers (12-month completion rate, 58%). Completion rates trended lower with the Ornish (50%) and Atkins (52%) diets than with the Zone and Weight Watchers diets (65% each).

Comment: In this small randomized comparison, each of four popular diets was associated with modest improvements in body weight and several cardiac risk factors at 1 year. Dietary adherence, which was generally low, yielded greater benefits. Further study is needed to determine whether individualized weight-loss strategies might optimize results. An editorialist advocates sustained behavioral change (increased physical activity and calorie restriction) -- a so-called "low-fad" approach that emphasizes persistence over quick fixes.

— JoAnne M. Foody, MD

Published in Journal Watch Cardiology February 11, 2005

Citation(s):

Dansinger ML et al. Comparison of the Atkins, Ornish, Weight Watchers, and Zone diets for weight loss and heart disease risk reduction: A randomized trial. JAMA 2005 Jan 5; 293:43-53.

• Original article (Subscription may be required)
• Medline abstract (Free)

Eckel RH. The dietary approach to obesity: Is it the diet or the disorder? JAMA 2005 Jan 5; 293:96-7.

• Original article (Subscription may be required)
• Medline abstract (Free)