Comparison of the Atkins, Zone, Ornish, and LEARN Diets Among Premenopausal Women

[Sherrie]

Comparison of the Atkins, Zone, Ornish, and LEARN Diets for Change in Weight and Related Risk Factors Among Overweight Premenopausal Women

The A TO Z Weight Loss Study: A Randomized Trial

Christopher D. Gardner, PhD; Alexandre Kiazand, MD; Sofiya Alhassan, PhD; Soowon Kim, PhD; Randall S. Stafford, MD, PhD; Raymond R. Balise, PhD; Helena C. Kraemer, PhD; Abby C. King, PhD

JAMA. 2007;297:969-977.

Context Popular diets, particularly those low in carbohydrates, have challenged current recommendations advising a low-fat, high-carbohydrate diet for weight loss. Potential benefits and risks have not been tested adequately.

Objective To compare 4 weight-loss diets representing a spectrum of low to high carbohydrate intake for effects on weight loss and related metabolic variables.

Design, Setting, and Participants Twelve-month randomized trial conducted in the United States from February 2003 to October 2005 among 311 free-living, overweight/obese (body mass index, 27-40) nondiabetic, premenopausal women.

Intervention Participants were randomly assigned to follow the Atkins (n = 77), Zone (n = 79), LEARN (n = 79), or Ornish (n = 76) diets and received weekly instruction for 2 months, then an additional 10-month follow-up.

Main Outcome Measures Weight loss at 12 months was the primary outcome. Secondary outcomes included lipid profile (low-density lipoprotein, high-density lipoprotein, and non–high-density lipoprotein cholesterol, and triglyceride levels), percentage of body fat, waist-hip ratio, fasting insulin and glucose levels, and blood pressure. Outcomes were assessed at months 0, 2, 6, and 12. The Tukey studentized range test was used to adjust for multiple testing.

Results Weight loss was greater for women in the Atkins diet group compared with the other diet groups at 12 months, and mean 12-month weight loss was significantly different between the Atkins and Zone diets (P<.05). Mean 12-month weight loss was as follows: Atkins, –4.7 kg (95% confidence interval [CI], –6.3 to –3.1 kg), Zone, –1.6 kg (95% CI, –2.8 to –0.4 kg), LEARN, –2.6 kg (–3.8 to –1.3 kg), and Ornish, –2.2 kg (–3.6 to –0.8 kg). Weight loss was not statistically different among the Zone, LEARN, and Ornish groups. At 12 months, secondary outcomes for the Atkins group were comparable with or more favorable than the other diet groups.

Conclusions In this study, premenopausal overweight and obese women assigned to follow the Atkins diet, which had the lowest carbohydrate intake, lost more weight and experienced more favorable overall metabolic effects at 12 months than women assigned to follow the Zone, Ornish, or LEARN diets. While questions remain about long-term effects and mechanisms, a low-carbohydrate, high-protein, high-fat diet may be considered a feasible alternative recommendation for weight loss.

Trial Registration clinicaltrials.gov Identifier: NCT00079573


Author Affiliations: Stanford Prevention Research Center and the Department of Medicine, Stanford University Medical School, Stanford, Calif.

In Full (PDF)

[Sherrie]

I thought I'd better get my butt into gear and put this up while I think of it before I totally forget about it, this is a week old now and was all the talk on pretty much every low carb website so you have probably seen it. Now the full text isn't free so I can't share that but I will share a couple of my favourite articles on it. Just keep in mind that though the atkins group did not do it properly they still were significantly more successful on all factors (if I remember right) despite eating the least carbohydrates and the most saturated fats.

Yes they regained on average around 3kg I think it was (sorry this isn't fresh in my mind) but they also increased their carbs to over 100g a day (maybe it was 130g?) so I bet it would have just been the water retention from the carb increase, really not a big deal imo and they STILL lost the most weight by a significant amount.

Anyway heres my two faves on this study:

Bad Science, Good Publicity by Regina

and

Low-Carb Diets Work -- and They're Healthy Mens Health Magazine

[LC_Dave]

I think the biggest thing I had learnt from this study:- Is the willingness of experts to stick to failed ideas, even in the absence of science that casts doubt on them.

The sad thing is I don't think it even made a dent in the low fat Intelligensia BS!

[Sherrie]

In Full (PDF)

[Sherrie]

Another good article regarding this study: More Science and Less Zealotry, Please.