South Beach Diet Is Hot; Here's Why

It started out simply enough. Arthur Agatston, MD, a cardiologist, decided to develop an eating plan that would improve the cholesterol and insulin levels of his patients with heart disease. Now, the South Beach diet has grown into something much bigger. That's because the plan Agatston created not only improves cholesterol and insulin levels, but it also has helped many people lose weight.

"We've had people lose anywhere from five to 100 pounds on the diet," says Agatston, who is director of the Mount Sinai Cardiac Prevention Center in Miami Beach, Fla. "That's great, but what it really is good at is improving heart patients' lipid profiles."

In clinical trials, people on the South Beach diet see dramatic reductions in LDL (bad) cholesterol and increases in HDL (good) cholesterol. And they do so without much calorie counting.

Agatston's book about his plan, The South Beach Diet: The Delicious, Doctor-Designed, Foolproof Plan for Fast and Healthy Weight Loss, has become a best seller and it appears to be poised to overtake the controversial Atkins diet in popularity.

"My medical orientation has always been in prevention," he says. "The diet grew out of the frustration in seeing more and more patients becoming obese, having metabolic syndrome and diabetes, and all the heart disease associated with those conditions."

Despite the South Beach diet's glitzy title, Agatston's research and inventiveness is well respected in cardiology circles. Among other achievements, he is one of the developers of the electron beam tomography scan, or EBT, a screening method used to detect coronary artery disease and other diseases. EBT scans for this purpose are given a score on the "Agatston Scale," to gauge the severity of the disease.

"This plan really does meet several criteria for a health-promoting diet," says Cindy Moore, RD, a director of nutrition therapy at The Cleveland Clinic in Ohio and a spokeswoman for the American Dietetic Association (ADA). "It appears to be scientifically based. It is rich in vegetables, fruits, whole grains, and lean protein, and it doesn't omit any major food groups."

So what is the South Beach diet all about?

In the first phase of the South Beach diet, which lasts two weeks, you eat normal-sized helpings of lean meats, such as chicken, turkey, fish, and shellfish. Vegetables are also allowed, as are nuts, cheese, and eggs. A salad with real olive oil dressing is fine. Coffee and tea are OK, and lots and lots of water is required.

The Atkins diet differs in that carbohydrates are severely restricted during the initial phase. The South Beach diet instead groups "good" and "bad" carbohydrates based on their glycemic index, a measure of how foods affect your blood sugar.

"The goal is to eat three balanced meals a day, and to eat enough so that you don't feel hungry all the time," Agatston says.

Forbidden in those first 14 days, however, are fruit, bread, rice, potatoes, pasta, or baked goods. No sugar, ice cream, cookies, or cake. And no alcoholic drinks of any kind (wine, fruit and whole-grain breads may be added back to the diet in subsequent phases).

Highly processed carbohydrates cause a cycle of overeating, says Agatston. White bread, for example, is digested quickly, resulting in a spike in insulin levels. Once the carbohydrates are used up, he says, you're left with too much circulating insulin, which causes your body to crave more food. Eating simple carbohydrates makes you want to eat more simple carbohydrates, and in the process, you gain weight, disrupt your lipid levels, and expose your cardiovascular system to unnecessary stress.

A typical South Beach diet breakfast is two eggs and lean bacon. Lunch is salad greens with grilled chicken. A small amount of dry-roasted nuts makes up an afternoon snack. Dinner is lean meat again with fiber-rich vegetables. Cheese and low-fat yogurt are allowed, as is sugar-free gelatin for dessert.

According to Agatston, at the end of two weeks, most South Beach dieters are eight to 14 pounds lighter. He says the weight loss doesn't happen because you're eating less, but rather because eliminating simple carbohydrates has broken a bad eating cycle. As a result, you'll continue to lose weight after the initial two-week period ends.

"I would like to see more backing to that specific weight-loss claim," says Moore, of the ADA. "While the first two weeks are heavy on protein, I'm not convinced that dropping carbohydrates would be enough to induce ketosis."

It's a well-established fact that rapid weight loss can be achieved when your body does not have carbohydrates to digest. This state is called ketosis.

Moore adds that despite the many positive aspects of Agatston's South Beach diet, you would be wise to work closely with a registered dietitian or your doctor with any diet that induces ketosis because the body is shedding water and, according to Moore, this might cause an electrolyte imbalance without proper hydration.

The second phase is similar to the first phase, but you'll start to reintroduce some of the banned foods. You can start eating high-fiber carbohydrates, such as whole-grain breads, which raise your insulin levels in a much milder way that do simple, starchy carbs.

"We don't want prolonged, severe weight loss," says Agatston. "You stay on the second phase only until you reach your goal weight."

The third phase of the South Beach diet is really all about weight maintenance, which Agatston describes as a "way of life." Should your weight begin to climb, you simply repeat the process.

"What's become clear recently is that the epidemic of obesity is caused partly by government health organizations promoting a carbohydrate-rich, low-fat diet, the kind you see in developing countries like China," says Agatston. "But those recommendations are based on people eating very high-fiber diets with low protein."

In the U.S., a carbohydrate-rich diet translates into lots of highly processed, low-fiber carbohydrates.

"The food we eat has often already been digested in the factory," says Agatston. "Eating white bread is like eating table sugar."

Though Moore agrees that the South Beach diet can be healthy, she reiterates the need for dieters to see a dietitian before trying it.

"The skill of a dietitian is to work within the parameters of what an individual needs," she says. "It's fine to use this diet for weight loss, but no diet fits everybody. For that reason, you need to work with someone to make sure the general diet is tailored to your particular body."

John Casey is a freelance writer who lives in New York City.

Published May 19, 2003.