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Fad diet overview: The South Beach diet

By H. K. Jones

Fad diets come and go faster than the latest colored charity bracelets. However, the South Beach diet seems to have some serious staying power. With book sales in the millions, and a recent alliance with the food giant Kraft Foods Inc. to produce an entire line of supermarket South Beach foods, this fad is worth a closer look.

Cardiologist Dr. Arthur Agatson developed the South Beach diet to help improve the heart health of his patients. He proposes that certain types of carbohydrates—the so-called "bad" carbs—create an impairment of the body's ability to process fat or sugar properly. He also believes, along with the entire medical community, that excess consumption of "bad" fats contributes to an increase in cardiovascular disease.

According to Agatson, a diet minimizing the "bad" (carbs and fats), and increasing the "good," will result in weight loss, lower cholesterol, a reduced risk of heart disease and diabetes, and eliminate cravings without feeling hungry. Hmmm...sound too good to be true? Let's spend a day at the South Beach and find out.

The Good News
As you might expect from a cardiologist, Agatson is concerned about fat, and that's good news for you and your arteries. In today's carb-crazed dieting world where low-carb, high-fat diets reign supreme, the South Beach approach to limiting fat is one of the diet's strongest selling points.

While popular diets like Atkins advocate unlimited amounts of fatty foods including cheese, bacon, and cream (loaded with artery-clogging saturated fat), the South Beach diet terms these fats "bad." This means lean red meat, skinless chicken, and reduced-fat cheeses remain on the menu, but foods like cream and butter are off limits. South Beach also places far more emphasis on the "good" monounsaturated and polyunsaturated fats such as olive oil.

Agatson also differentiates between good and bad carbohydrates. Spend a day at the South Beach and you'll learn that the "good" carbs are foods with a low glycemic index (GI), which means they are digested and absorbed slowly. The GI system is simply a scientifically sound way of describing how the carbs in foods affect blood glucose levels when digested. Low-GI foods do not radically affect blood glucose levels; high-GI foods do.

The South Beach diet also promotes eating carbohydrates that have more nutritional value than their processed alternatives. For example, the diet allows brown rice in moderation, but discourages consumption of white rice. Diets based on low-GI foods generally encourage you to "de-junk" your diet and cut down on foods with few nutrients, such as refined white bread, sugary cereals, and sweets.

While nutrition experts and dietitians are generally in favor of diets based on the GI index, they don't necessarily think all high-GI foods should be banned and deemed "bad". This is because the GI value of a meal changes considerably when foods are eaten together. That said, few experts would argue that cutting down on processed carbs is a bad idea.

The diet also emphasizes making a permanent change in your lifestyle and way of eating, instead of just a quick-fix weight-loss solution. That's good news for people who understand that eating well and maintaining healthy body weight is a lifelong commitment. Now for the bad news...

The Bad News
Like many diets, the South Beach is divided into three phases. In phase one, you stop eating almost all carbohydrates to give your body a complete rest from fluctuating blood sugar and insulin levels. The theory is this will help to resolve insulin resistance. In reality, extreme carbohydrate restriction during this phase will leave you feeling weak and wobbly, and you will also be cutting out good sources of vitamins, minerals, and fiber. While the South Beach diet allows a few low GI veggies, such as broccoli and cabbage, during this initial phase, it focuses you on primarily eating lean meat, chicken, fish, eggs, low-fat cheese, some nuts, and olive oil. You follow this phase for a torturous and unhealthy 14 days.

In phase two you get a little relief from the carb-starving as the diet allows you to reintroduce some low-GI carbs into your diet, including most fruits, whole wheat bread, whole grain cereals, pasta, and low-fat milk. You stay with this phase until you've reached your target weight.

Once you have reached your target weight, you are ready for phase three. In phase three you introduce an even wider variety of foods. Phase three aims to keep your weight steady and the diet recommends you stay on this phase for life.

In addition to its outrageous restrictions requirements, phase one of the South Beach diet also promotes an extreme amount of weight loss in a short period of time. A staggering weight drop of "13 pounds in two weeks" is downright unhealthy, and will simply be the result of severe calorie restriction caused by cutting out all carbs. General nutritional guidelines recommend losing no more than two pounds per week to maintain good health. This puts the South Beach at nine pounds over the healthy limit.

The diet also promises you will lose weight specifically from your midriff. However, most nutrition and fitness experts believe it's impossible to lose fat from just one part of your body.

The Bottom Line
The South Beach diet is a healthier version of the Atkins diet backed by solid science on fats and heart disease. While the severe fruit, vegetable, and whole grain restrictions recommended in phase one and two of the diet are not only unhealthy, but also just silly and unnecessary, the lifetime plan outlined in phase three offers a solid approach to eating.

H. K. Jones is a registered dietitian, freelance writer, and nutrition professional based in Washington, DC.