Atkins tops 3 other popular diets for women: study
Last Updated: Tuesday, March 6, 2007 | 3:50 PM ET
The Canadian Press
Women who followed the Atkins low-carbohydrate diet lost more weight over a year than those on three other popular diets, and their blood pressure and cholesterol levels also dropped to a greater degree, a study has found.
On average, women randomly assigned to the Atkins diet lost 10.4 pounds after 12 months, compared to 5.7 pounds for women on the LEARN diet, 4.8 pounds for Ornish diet followers and 3.5 pounds for those on The Zone weight-loss plan.
Individual results varied, however, with some participants in all four groups losing up to 30 pounds, says the study by Stanford University researchers, published Wednesday in the Journal of the American Medical Association.
"Many health professionals, including us, have either dismissed the value of very low-carbohydrate diets for weight loss or been very skeptical of them," said lead researcher Christopher Gardner, an assistant professor of medicine at the Stanford Prevention Research Center in California. "But it seems to be a viable alternative for dieters."
In the $2-million US study, 311 premenopausal, non-diabetic, overweight women were randomly assigned to follow one of the Atkins, Zone, LEARN (Lifestyle, Exercise, Attitudes, Relationships and Nutrition) or Ornish diets.
The four diets were chosen to represent a spectrum of low- to high-carbohydrate weight-loss plans:
- The Atkins diet is the lowest in carbohydrates.
- The Zone diet, also low-carbohydrate, focuses on a 40:30:30 ratio of carbs to protein to fat, a balance said to minimize fat storage and hunger.
- The LEARN diet follows guidelines in the U.S. Department of Agriculture's food pyramid — low in fat and high in carbohydrates.
- The Ornish diet is very high in carbohydrates and extremely low in fat.
At the end of the study, women following the Atkins diet had larger decreases in body mass index, triglycerides and blood pressure compared to women in the other three groups. As well, their high-density lipoprotein (HDL), the good kind of cholesterol, increased more than that of women on the other diets.
Easier more effective?
Gardner believes there are several reasons why the Atkins diet had better results overall.
"It's a very simple message," he said in a release. "Get rid of all refined carbohydrates to lose weight."
Besides targeting high intake of sugar and refined-flour products, the Atkins diet is the best at encouraging people to drink more water, said Gardner, noting that when people replace sweetened beverages with water, they don't generally eat more food but consume fewer calories over the course of a day.
Dr. Arya Sharma, chair of cardiovascular obesity research at McMaster University, said it appears that diets like the Atkins plan are easier for people to adhere to because the high-protein content is more filling.
"Patients are less hungry and tend to eat less overall with these diets than with other diets, where there are more or less restrictions in the kinds of foods that patients can eat," Sharma, scientific director of the Canadian Obesity Network, said Tuesday from Hamilton.
"So it's not surprising that patients lost more weight on the Atkins diet."
Keeping pounds from creeping back
Still, the study showed that although the Atkins dieters shed the most pounds by the end of the year, they also gained back more weight in the second half of the study than those in the other three groups.
Gardner said the women in the Atkins group had lost an average of almost 13 pounds after six months, but ended the one-year period with a final overall average loss of 10.4 pounds.
Sharma, calling the study important because it is the first to do such a large head-to-head comparison of popular diets, said the trick to being successful with any diet is keeping lost weight from piling back on.
"What's quite clear is that patients who have obesity and need to lose weight and keep that weight off cannot eat like other people," he said. "They have to make dietary changes in the long term. It's like if you have diabetes, you can't eat like everybody else."
