Atkins Beats Other Diet Plans in Study

CHICAGO - The low-carb, high-fat Atkins diet gets high marks in one of the biggest, longest head-to-head studies of popular weight-loss plans, beating the Zone, the Ornish diet and even U.S. guidelines. Even so, critics say the results show how hard it is to lose weight and keep it off.

Overweight women on the Atkins plan lost more weight over a year than those on the low-carb Zone diet. And they had slightly better blood pressure and cholesterol readings than those on the Zone; the very low-fat, high-carb Ornish diet, and a low-fat, high-carb diet similar to U.S. government guidelines.

Stanford University researcher Christopher Gardner, the lead author, said the study shows that Atkins may be more healthful than critics contend.

But the study isn't a fair comparison because by the end, few women were following any of the diets very strictly, critics argue, although those in the Atkins group came the closest.

The study "had a good concept and incredibly pathetic execution," said Zone diet creator Barry Sears.

"It's a lot easier to follow a diet that tells you to eat bacon and brie than to eat predominantly fruits and vegetables," said Dr. Dean Ornish, creator of the Ornish diet.

Atkins followers lost about 10 pounds on average at 12 months, versus 3.5 pounds for the Zone dieters.

Women on the Ornish diet lost almost 5 pounds on average and those on the national guidelines plan lost almost 6 pounds. Scientifically, those 12-month results weren't different enough from the Atkins weight loss to rule out the possibility the differences occurred by chance.

The dieters lost the most weight early on, including an average of 13 pounds for the Atkins group at six months - nearly double the closest competitor, the national guidelines diet. After that, most began regaining weight, a trend most noticeable in the Atkins women.

With an average starting weight of about 189 pounds, even losing 13 pounds meant many women remained overweight.

"There's not a ton of weight loss here," Gardner acknowledged. Atkins "isn't the solution for the obesity problem," he said.

The study involved 311 women about 40 years old on average and was designed to measure the effectiveness of using a diet book to lose weight. Women were randomly assigned to read one of four diet books. They attended weekly classes for eight weeks where diet questions were addressed, but then were mostly on their own for the next 10 months.

At the end, Atkins women had slightly higher levels of HDL cholesterol, the good kind, and slightly lower blood pressure than those on the other three diets. Gardner said differences in weight loss likely contributed to those results.

Ornish and other naysayers argued that the study doesn't answer a big question about the Atkins diet - whether consistently eating all that fatty food long-term leads to health problems.

The authors said it's uncertain whether the results would apply to men or older women since none were studied.

The study "shows that nothing works very well," said Yale University food policy researcher Kelly Brownell. His book promoting diet and lifestyle changes similar to national guidelines was used in the study.

The results echo a Harvard study published last year involving thousands of women, which also suggested that a low-carb high-fat diet might be more heart-healthy than previously thought, although it relied on women's memories of what they had eaten over two decades.

Also, those who ate fat and carbs from vegetables rather than animal sources had lower heart disease risks in the Harvard study.

Dr. David Katz of the Yale Prevention Research Center and author of several weight control books, said the new study presents little new information and called it "much ado about nothing."

Nurse Jackie Eberstein, whose consulting company promotes the Atkins diet, said the results are not surprising. Protein makes people feel less hungry and fat helps them feel more full, which makes weight loss easier on Atkins, she said.

Study participant Viola Manges, who does administrative work at Stanford, was assigned to the Atkins group.

Manges, 41, said the diet taught her to make healthier food choices, like eating steamed vegetables instead of mashed potatoes, even if she didn't always follow it strictly.

Manges lost roughly 23 pounds, slimming down to a size 6 by the study's end about a year ago. She has regained about 10 to 15 pounds, but said she still tries to follow some of the Atkins recommendations.

The study was funded by grants from the National Institutes of Health and from the Community Foundation of Southeastern Michigan.

Dieting? Low-carb might be the way to go, at least in the short-term. Stanford University researchers comparing three popular diets over a year found that overweight women lost the most weight on the low-carb, high-protein Atkins diet, much maligned by nutritionists in recent years. Although their weight loss was modest, the Atkins dieters also saw drops in blood pressure and cholesterol levels, indicators of improved heart health. The $2 million study, sponsored by the National Institutes of Health and published in Wednesday's Journal of the American Medical Association, is the largest controlled trial to date of the Atkins, Zone and Dean Ornish diets.

It adds to a growing body of evidence that low-carb diets can help people shed more pounds than low-fat, high-carb eating plans, but it's also likely to elicit renewed protests from nutritionists who maintain that any diet promoting meat and cheese over fruit and whole grains can't be good for your health in the long run. "I'm puzzled by how stubbornly nutrition authorities continue to dismiss the Atkins diet because it's counterintuitive and high in animal fat," said Dr. Michael Dansinger, a Tufts-New England Medical Center researcher who conducted a similar, but smaller, popular diet comparison published in JAMA in 2005. "Rather than dismissing it, we should be trying hard to learn from it."

Millions of people have tried the Atkins, Zone and Ornish diets, and the Stanford researchers tried to recreate the real-world conditions under which most dieters try to lose weight: on their own, with a best-seller in hand. The Atkins diet severely restricts carbohydrates such as bread, pasta and fruit while allowing cheese, oils and meats largely verboten in many diets. The Ornish diet was designed to reverse heart disease and severely limits fat in favor of fruits, vegetables and grains. The Zone diet aims to control insulin levels by strictly limiting calories and dividing them into 40 percent carbohydrates, 30 percent protein and 30 percent fat.

The Stanford researchers recruited 311 overweight or obese women aged 20 to 50 and split them into four groups. Three of the groups were assigned to follow the Atkins, Zone or Ornish diets for a year, and were given the best-selling books for that diet. A control group was asked to follow the LEARN diet, a low-fat, high-carb eating plan recommended by the federal government. Then the women were largely left alone, save for an eight-week nutrition class and checkups at two, six and 12 months. They were encouraged to do whatever exercise was recommended in the diet books they were given, and they prepared their own meals and bought their own food.

Although some women in each of the four groups lost as many as 30 pounds, the average participant lost far less. The Atkins dieters lost, on average, 10.4 pounds, while the women in the control group lost 5.7 pounds. The Ornish dieters lost a little under five pounds, while the Zone dieters lost the least, with an average drop of 3.5 pounds. Some nutrition experts have worried that the Atkins diet, high in animal fat and protein, could raise cholesterol and blood pressure, but their concerns were not borne out in this study and some other recent studies. The Atkins dieters' "good cholesterol" levels rose compared with the other diet groups and blood pressure declined compared with some of the other diet groups.

The researchers noted that the weight lost by the Atkins dieters was only statistically significant when compared with the Zone dieters. Given that fewer than 80 women were in each group, the differences in weight loss between the Atkins and the Ornish and control-group dieters could have happened by chance. There were no statistically significant differences between the Ornish, Zone and control groups. Still, women who want to lose weight probably will be intrigued by the Atkins dieters' results, which echo some previous studies showing that low-carb diets seem to peel off the pounds, at least temporarily.

That dismays Dr. Dean Ornish, who founded the non-profit Preventive Medicine Research Institute in Sausalito. Ornish, a leading proponent of very-low-fat diets, criticized the study, saying that the group assigned his diet did not really follow it - they reported eating far more fat than his diet allows. "I'm concerned that this study may cause people to forgo eating a healthy diet for one that's actually harmful for them," he said. Lead author Christopher Gardner, an assistant professor of medicine at the Stanford Prevention Research Center, said the study wasn't designed to test perfect compliance with any of the diets, but rather how they work under real-world conditions. It may be that the Atkins diet's emphasis on protein helped dieters feel fuller sooner and stay that way longer, he said. The diet has "one of the simplest messages to get out there for weight loss: absolutely no sugar and no refined carbs," Gardner said.

He cautioned, however, that the study was not designed to look at its long-term health effects and that the Atkins diet may impair bone density and kidney function. "We're all nervous about the long-term effects of a high saturated fat diet," he said. What's more, he said, as the study progressed, some dieters put back on some of the weight they had lost early in the year. That happened to Tania Bailey, a 47-year-old woman who was part of the Atkins group. She has regained about 10 of the 30 pounds she lost during the year-long study, but is holding steady with a less-restrictive, but still low-carb, diet. "I had a very boring diet," Bailey said of her participation in the study. "I ate Brie, so many high-fat foods. I had a lot more energy. I don't know why I couldn't stick with it."

The key word is "boring," said Kathryn Sucher, a nutrition and food science professor at San Jose State University. That, she said, is the reason so many people drop off the Atkins diet and other highly restrictive eating plans. "I jokingly say the best diet is the one you can stick with," Sucher said. "People think somehow that there's this magical bullet that'll help them lose weight, but losing weight is really about changing your lifestyle. And it's really hard to change people's lifestyles." For more information on the diet study and ongoing nutrition studies at Stanford, visit http://nutrition.stanford.edu
http://jama.ama-assn.org/cgi/content/abstract/297/9/969

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