WASHINGTON, Feb. 24 — Several of the nation's best-known nutritionists and diet promoters agreed on very little today when they sat down for what the Agriculture Department billed as ''the great nutrition debate.''
In one corner was Dr. Barry Sears, creator of the high-protein Zone diet, and Dr. Robert Atkins, namesake of the Atkins Diet and a brand of nutritional supplements, who agreed on the supposed dangers of pasta, potatoes and other carbohydrates.
In the other corner was Dr. Dean Ornish, author of five best-selling diet books, including ''Eat More, Weigh Less,'' who scoffed at high-protein diets and said pasta and white bread were just fine as long as they were low in fat.
Agriculture Secretary Dan Glickman said the department decided to sponsor a debate between the diet heavyweights because ''there is so much confusing, conflicting information out there'' about which diets work. According to the department, Americans spend about $50 billion a year on weight-loss regimens.
The scientific validity of some of the nation's most popular diets was a concern for several dietitians who participated in the debate.
''Remember about 10 years ago there was the Beverly Hills diet -- the one that was going to take us from hamburgers to hip bones?'' asked Dr. Keith-Thomas Ayoob, a pediatric nutritionist at Albert Einstein College of Medicine in New York and a critic of quick-fix dieting.
''Diets don't work,'' said Dr. Ayoob, who favors weight loss through low-fat, balanced meals. ''The word itself suggested a limitation.''
Dr. Denise Bruner, the president of the American Society of Bariatric Physicians, agreed. (Bariatrics is the study of obesity.) She cited supersized hamburgers, french fries, television and Americans' sedentary jobs and lives as reasons for obesity.
By the time the three-hour debate was over, so many conclusions had been drawn that almost no one in the audience seemed convinced that they knew what the best diet was. The only two things the dietitians did agree on was that exercise was a good thing and dieters should stay away from candy.
''It was eye-opening,'' said Lori Tubbs, a civil service dietitian for the Navy who drove four hours from Fort Eustis in Newport News, Va. She said she rejects most of the fad diets. ''I think that it needs to be a balanced diet,'' she said.
