Atkins wins for losing
The largest and longest-running comparison of diet plans found the low-carbohydrate Atkins regimen produced greater weight loss than three other popular programs -- the Zone, the Ornish and the U.S. nutritional guidelines.
The average weight reduction was small, and participants started regaining pounds by the end of the one-year study, according to the report in today’s Journal of the American Medical Assn.
Still, Atkins dieters -- who consume prodigious amounts of long-demonized saturated fats but shun carbs, such as pasta and breads -- experienced significant drops in blood pressure and cholesterol.
The finding showed that even a small weight reduction can improve overall health, researchers said.
Atkins dieters lost an average of 10.4 pounds after one year, according to the report, compared with 5.7 pounds for those on a traditional balanced diet based on federal nutritional guidelines, 4.8 pounds for the high-carbohydrate Ornish diet and 3.5 pounds for the Zone diet, which calls for a set ratio of carbohydrate, protein and fat.
The study’s results cast further doubt on the benefits of low-fat, high-carb diets, which have been touted for decades as the model of healthy eating.
“This study confirms the importance of reducing carbohydrates,” said Dr. Frank Hu, associate professor of nutrition and epidemiology at the Harvard School of Public Health, who was not involved in the research. “Bagels, white bread, potatoes and soft drinks are the real bad guys in our diet.”
The study was quickly criticized by some Atkins competitors.
Dr. Dean Ornish, president of the Preventive Medicine Research Institute in Sausalito, Calif., said the differences among the weight loss plans detected in the study were insignificant.
He added that Atkins dieters saw an increase in levels of LDL, or “bad,” cholesterol.
“The conclusions of this study are highly misleading,” he said.
But Atkins backers saw the study as vindication of their approach and predicted a revival of interest in the Atkins diet, whose popularity peaked five years ago but then swiftly faded.
Atkins Nutritionals Inc., which sold packaged foods based on the diet, sought bankruptcy protection in 2005. Today, the $2-billion carb-conscious food market is dwarfed by the $14.7 billion spent on low-fat products, according to AC Nielsen.
“Those of us who have been in the low-carb community for decades are not surprised by these [study] results,” said Jacqueline Eberstein, coauthor of “Atkins Diabetes Revolution” with Dr. Robert C. Atkins, who died in 2003.
The $2-million diet faceoff, funded by the National Institutes of Health and the Community Foundation for Southeast Michigan, was conceived several years ago to sort out the cacophony of claims made by competing diet plans.
More than 300 overweight, pre-menopausal women were randomly assigned to follow one of the four diet plans, which were chosen to represent a range of low- to high-carbohydrate diets. The Zone and the traditional diet, called LEARN, included calorie-restriction goals, but the Atkins and Ornish diets did not.
When the study began, the women weighed an average of 190 pounds and had an average body mass index of more than 30, putting them in the obese range. BMI is a standard measure that takes into account a person’s weight and height.
Participants attended weekly diet classes for the first eight weeks and received a book outlining their specific dietary program. The women’s weight and metabolism were regularly checked, and their diets were monitored by phone.
The women prepared their own meals, and some had trouble sticking to their diet regimens, mimicking real-world conditions.
Lead author Christopher D. Gardner, a Stanford University assistant professor of medicine, said one reason the women on the Atkins diet lost the most weight was because the program was easy to follow.
“It has a very simple message: Get rid of all the junk carbohydrates,” he said.
In fact, Gardner said he suspected that the bulk of the weight loss in the Atkins program came from women substituting water for soft drinks.
In addition, Gardner said, the Atkins diet’s reliance on higher amounts of protein, which is more filling than carbohydrates, may have kept women from feeling too hungry.
He also noted that Atkins dieters saw sharper drops in triglycerides, a type of fat, and blood pressure, and steeper increases in HDL, or “good,” cholesterol than women on the other diets, according to the study.
The improvements could have important public health implications, Gardner said.
“The good news is that a small amount of weight loss is very powerful,” he said.
The results show the Atkins diet is a reasonable choice for short-term weight loss, said Gardner, a vegetarian.
Hu cautioned against using the study as an excuse to indulge in sausage and bacon at every meal. A lifetime of eating large amounts of foods rich in saturated fat could increase the chance of heart disease, he said. More healthful fats can be found in peanut butter, legumes and vegetable oil.
Mara Vitolins, professor of public health sciences at Wake Forest University Baptist Medical Center in Winston-Salem, N.C., who was not involved in the study, noted another drawback: The Atkins diet is relatively low in fruits and vegetables, which contain nutrients that are believed to have a protective effect against heart disease and cancer.
Marion Nestle, professor of nutrition, food studies and public health at New York University, who also was not involved in the study, said the findings should be interpreted cautiously.
Women on the Atkins diet experienced most of their weight loss during the first six months, raising the possibility that weight loss on all four diet plans would look the same in a longer study, she said.
“My guess is that if they carried this study out for another six months, they would converge,” Nestle said.
Dr. Kelly Brownell, director of the Yale Center for Eating and Weight Disorders and creator of the LEARN diet, which includes exercise and behavior modification, said the real message of the study was that better approaches were needed to address obesity.
“What the study shows is that the best treatments we have are not very effective and all work about the same,” he said. “Overall, this shows for the umpteenth time how hard it is to treat obesity and the best cure is preventing the problem.”
A study of popular diets found the low-carbohydrateAtkins plan led to greater weight loss.
Results in 12-month period (averages)*
*--* Atkins Zone LEARN Ornish (lo-carb) (carb/prtn/fat) (traditnl) (hi-carb) Weight loss (pounds) 10.4 3.5 5.7 4.8 Body fat (% loss) 2.9 1.3 1.0 1.5 HDL cholesterol** (mgms/deciliter) +4.9 +2.2 +2.8 0 LDL cholesterol** (mgms/deciliter) +0.8 0 +0.6 --3.8
*For women weighing an average of 190 pounds. **HDL, high-densitylipoprotein (“good” cholesterol); LDL, low-density lipoprotein (“bad"cholesterol)Source: Journal of the American Medical Assn.Los Angeles Times