http://www.nytimes.com/2003/10/07/h...ion/07DIET.html


New Doctor, New Diet, but Still No Cookies
By ABBY GOODNOUGH

IAMI BEACH, Oct. 6 — Theories abound as to what has propelled the South Beach diet to the center of the weight-loss universe since the book bearing its name was published in April. Is it the image it conjures, of bikini-clad models picking at tropical fruit salad between sun-drenched photo shoots? Is it the aqua shimmer of the book jacket, as eye-catching as the surf off Ocean Drive?

Or is it that Dr. Arthur Agatston, the cardiologist behind the latest low-carbohydrate, high-protein diet, is on to something?

Dr. Agatston — whose office is not in South Beach, by the way, but the older, tamer neighborhood to its north — is not far from that giant of diet doctors, the late Dr. Robert Atkins, in his belief that refined sugar and white flour are the villains behind the nation's climbing obesity rate. Like the Atkins diet, the South Beach diet strictly limits bread, potatoes and other carbohydrates, especially during a two-week initiation period, and allows the dieter to eat red meat, eggs and cheese.

But while the Atkins diet allows just about any fatty food that is not also starchy, Dr. Agatston advocates mostly unsaturated fats, like those in olive oil, nuts and oily fish like salmon. Butter is nowhere in the South Beach diet meal plans, nor is bacon or anything fried. The South Beach diet also differs from Atkins in that it allows carbohydrates — though only those high in fiber, like multigrain bread and wild rice.

Dr. Agatston's premise is that most carbohydrate-rich foods are so processed that they immediately turn to sugar in the body. That, Dr. Agatston says, forces a quick spike in blood sugar and nearly as quick a decline. The spikes lead to more hunger, he says, and — this is the part that many experts dispute — to inevitable weight gain.

"Nobody in the history of man ever ate complex carbohydrates like we have," Dr. Agatston said last week during an interview squeezed between a photo shoot and a meeting about his new heart-imaging center, set to open in December. He was late to the interview, so his wife, Sari, a lawyer who is helping with publicity, filled the time by talking about how even she, a bread lover, has come to accept whole-wheat pita instead.

The diet revolves around the glycemic index — the amount that a carbohydrate increases sugar in the blood compared with the amount that the same quantity of white bread raises it. The concept of the index as crucial to weight gain or loss has been around since the early 1980's, when it was used to help people with diabetes choose proper diets. But skeptics — including the American Diabetes Association, which has not endorsed the index — say a food's glycemic index fluctuates depending on how much is eaten and what other foods are eaten.

Foods with a low glycemic index, like lentils, soy milk and low-fat, artificially sweetened yogurt, do not raise blood sugar as quickly and sharply as high-numbered items like gnocchi, baked potatoes and pretzels.

High-glycemic-index foods cause the body to release a lot of insulin, which quickly lowers the blood sugar again and causes hunger to recur, the theory goes. Those with low indexes break down into sugar more slowly, for longer-term energy.

Carrots are shunned, for example, because the body absorbs their sugars rapidly. But Dr. Marion Nestle, chairwoman of the department of nutrition and food studies at New York University, said it would take over a pound of carrots to spike the blood sugar as high as the index warns.

"What it comes down to is that this is a standard 1,200- to 1,400-calorie-a-day diet, so of course people are going to lose weight," Dr. Nestle said. "I do think there's something to the glycemic index, but I just don't think it's the be-all and end-all, and that it's the root of obesity."

Dr. Nestle and other experts said they preferred South Beach to Atkins because it promotes only healthy foods. Several studies suggested the high-fat Atkins diet was safe for the heart in the short term, though Dr. Gary Foster, an author of one study, said the South Beach diet seemed "more informed."

"If this approach says: `Guess what. We think saturated fat is a bad idea,' it will get a greater mass acceptance," said Dr. Foster of the weight and eating disorders program at the University of Pennsylvania.

"If you compare the two menu to menu there is very little difference" between the strict first phases of the Atkins and South Beach diets, said Colette Heimowitz, director of education and research for Atkins Nutritionals. "It's a myth that Atkins is all about meat and discourages healthy fats."

The first two weeks of the South Beach diet are the most difficult, according to testimonials in Dr. Agatston's book, because they allow only foods with the lowest glycemic indexes. Fruits, juices, alcohol, caffeinated coffee and most dairy foods are forbidden. Dessert is part-skim ricotta cheese mixed with cocoa powder or almond extract. The closest thing to starch is "Surprise South Beach Mashed `Potatoes,' " otherwise known as puréed cauliflower.

The goal is to stabilize the blood sugar, and with it, the appetite. The book promises weight loss of up to 13 pounds in the first two weeks, which some dietitians see as a red flag.

"Any time you're promised a weight loss of over a pound a week, which is the safe recommended amount, it's time to say, `What's going on here?' " said Dawn Jackson, a dietitian at Northwestern Memorial Wellness Institute in Chicago, who reviewed the diet for the American Dietetic Association.

Yet Ms. Jackson said she liked Phases 2 and 3. In those, fiber-rich carbohydrates and unsaturated fats are gradually reintroduced. Participants are supposed to stay in Phase 2 until they reach their desired weights, then move on to Phase 3 indefinitely. But it's back to Phase 1 if they regain pounds, a step Ms. Jackson warned verged on the unhealthy.

"If you don't read it for Phase 1 and just look at the healthy menu plans in Phases 2 and 3, it's a good book for that," she said. "It's definitely healthier than Atkins, but at the end of the day, if you are losing weight on this diet it's because you're eating fewer calories than you did before."

Dr. Agatston agrees, but says people consume fewer calories because his diet has banished their cravings by stabilizing blood chemistry.

"The measure of whether the diet is working is, Are you getting cravings in the late afternoon and in the evenings?" he said. "People who do really well lose 40 pounds and perhaps gain back 5 to 10, but their blood chemistries continue to do well and they don't get the cravings."

There is no scientific data on the South Beach diet except for a study that Dr. Agatston conducted with some of his own patients, but the study did not follow them long term.

There are many converts from Atkins based on the postings on Internet message boards, some saying South Beach offers more variety.

The Atkins diet puts people into ketosis, a condition in which the body converts stores of fat into energy because it has been deprived of sufficient carbohydrates. While ketosis is not dangerous for healthy people, Dr. Agatston said, he did not want his diet to induce it because the patients he designed it for had hypertension.

Dr. Bonnie Brehm, an assistant professor at the University of Cincinnati who has studied low-carbohydrate diets, said both Atkins and South Beach dieters should be monitored long term for the effects on kidney function, since high-protein diets make the kidneys work harder. High protein intake can also strip the body of calcium, Dr. Brehm said.

Despite their precautions, Dr. Brehm and other experts favor diets rich in high-fiber carbohydrates and unsaturated fats. Dr. Agatston is riding out the trend, finishing "The South Beach Diet Cookbook," due out in April, and a guide to good fats and carbohydrates. "The South Beach Diet," which had an initial run of 55,000 copies, has 4 million copies in print in less than 6 months, and nearly 100,000 people have subscribed to the diet's Web site. South Beach residents seem to have embraced it; the local bookshop cannot keep it in stock, and stores run out of its recommended foods — like Laughing Cow cheese.

And while the book has stayed on the New York Times best-seller list for 25 weeks, a newcomer has knocked it out of the No. 1 spot in the "advice, how-to and miscellaneous" category: "The Ultimate Weight Solution" by Dr. Phil McGraw. Dr. McGraw asserts that people overeat for emotional reasons, a concept that Dr. Agatston sniffs at.

"I don't buy that the cause of obesity in this country is stress," he said. "The least stressful decade in this country was the 90's, and that's when this country got fat."

But Ms. Jackson, the Chicago dietitian, said Dr. McGraw's focus on changing attitudes toward food and toward exercising more made good sense.

"The idea of `Don't look to a diet book to fix everything but make small changes to what you're already doing' is one I'd like to see more of," she said.