What Is the Best Diet?

May 7, 2007 -- Volumetrics is the best carefully researched diet plan, and The Best Life Diet is the best diet book, Consumer Reports says.

Volumetrics is based on the research of Penn State nutritional science professor Barbara Rolls, PhD. The Volumetrics diet stresses eating foods with low "energy density" -- that is, foods with relatively few calories per portion. Such foods include fruits, salads, and soups.

The Best Life Diet, by personal trainer and exercise physiologist Bob Greene, stresses exercise and gives personalized advice, including recipes and a recommended eating schedule.

To rate the diet plans, Consumer Reports Senior Project Editor Nancy Metcalf and colleagues reviewed diet studies published in major medical journals. After Volumetrics, Metcalf's team ranked Weight Watchers, Jenny Craig, and Slim-Fast "very close together."

The report gave middling ratings to eDiets and to Barry Sear's The Zone Diet. Bringing up the rear were Dean Ornish's Ornish Diet and, in last place, the Atkin's Diet.

To rate the diet books -- newer diets that, according to Consumer Reports, "have not been put to the acid test of a large clinical trial" -- the CR staff applied their own criteria and also got input from a panel of nutritional experts.

After The Best Life Diet, CR ranked three books as "very close to one another:" Eat, Drink, & Weigh Less by Mollie Katzen and Walter Willett, MD; You On a Diet, by Michael F. Roizen, MD, and Mehmet C. Oz, MD; and The Abs Diet by David Zinczenko with Ted Spiker.

Ranked last among the diet books -- behind The South Beach Diet by Arthur Agatston, MD; and The Sonoma Diet by Connie Guttersen, PhD, RD -- was Ultra-Metabolism by Mark Hyman, MD.

The ratings appear in the June issue of Consumer Reports.

Diet Authors Respond

"We set up criteria that make sense to us, and let the chips fall where they may -- hopefully not chocolate chips," Metcalf tells WebMD. "The things that go into the rating are the nutritional analysis -- we analyze a week's worth of menus straight off the book or web site -- and we also rate them according to how well they conform to the 2005 U.S. dietary guidelines, which we think is a good consensus on a healthy diet."

For the diet plans, that may not have been the best strategy, says low-carb-diet expert Eris Westman, MD, associate professor of medicine at Duke University Medical Center. Westman was a member of the Consumer Reports expert panel that helped rank the diet books.

"When you compare a weight loss diet to a healthy-eating guideline, of course it is going to look bad because it is restricted in calories and, perhaps, in carbohydrates," Westman tells WebMD. "This is a common point of confusion. If you have diabetes, can you follow the healthy-diet guidelines? No! You are not healthy: You have diabetes and need a different kind of diet."