What Is It?

The South Beach Diet was initially developed by Miami, Florida-based cardiologist Dr. Arthur Agatston and dietician Marie Almon. It was created to help Dr. Agatston's patients lower their risk of developing heart disease. At the time, the most popular — and American Heart Association-approved — diets were built around low-fat, high-carb eating plans. But Dr. Agatston found that this diet was just not effective in the long run. When told to avoid unhealthy fatty foods, he hypothesized that his patients (and most Americans) switched over to consuming way too many additional sugars and other simple carbs.

So, Dr. Agatston developed a replacement: the South Beach Diet. The South Beach Diet is meant to be simple and accessible. The basic premise is to replace "bad carbs" with "good carbs" and "bad fats" with "good fats." Bad carbs, according to the South Beach Diet, are those with a high glycemic index — those foods that increase your blood sugar at an especially fast rate. According to Dr. Agatston, carbs with a high glycemic rate make you feel hungry even when your body has all the food you need. The South Beach Diet eliminates carbs with a high glycemic rate, such as refined sugars and processed grains, in favor of unprocessed foods, such as vegetables, beans, and whole grains. The South Beach Diet also replaces foods heavy in saturated fats with foods rich in unsaturated fats and omega-3 fatty acids.

The South Beach Diet has three distinct phases:

  • Phase 1: Two weeks, during which all sugars, all fruits, and most carbohydrates are banned. You also cannot drink any alcohol, including beer and wine, during the first phase.
  • Phase 2: This is the weight loss phase. During Phase 2, the "good carbs" are reintroduced into the diet. These include whole-grain breads, whole-grain pastas, most fruits, and some treats. This phase lasts as long as the dieter wants to lose weight.
  • Phase 3: It starts when you have reached your target weight, as it is the maintenance phase and is meant to be lifelong. There are no specific rules for Phase 3. The idea is that the participant should feel as though they are adopting a permanent lifestyle change, where they will continue to make the right food choices for the rest of their life.
thumbs up Pro
  • On this diet there are lots of things you can eat, and you can even snack throughout the day.
thumbs down Con
  • Followers of the South Beach Diet may fall off the wagon relatively quickly because there aren’t severe restrictions in this diet.

The Promise

The South Beach Diet promises to help you lose weight through maintaining a balanced diet that is rich with nutrients and fiber. It claims that you'll lose 8 to 13 pounds during phase 1 and then 1 to 2 pounds a week during phase 2. Proponents of the South Beach Diet like to claim that it's the "anti-fad fad diet," insisting that, unlike many other branded diets, this one is effective in the long run. The diet distinguishes itself with claims that it will teach you to consistently choose "good" carbs over "bad" carbs and not just count calories.

Because the South Beach Diet was conceived of initially as a means to be more heart-healthy, it also promises to improve your cardiovascular health, providing a number of auxiliary health benefits that are sometimes, but not necessarily, weight-related, including:

  • a lowered risk of developing type 2 diabetes
  • a lowered risk of high blood pressure
  • normalized cholesterol levels
  • normalized blood fat levels

Pros and Cons

You definitely won't go hungry on this diet. There are lots of things you can eat, and the diet even promotes snacking throughout the day (to avoid gorging at meal time). The South Beach Diet promotes a balanced diet and doesn't require any carb or calorie counting. Because the South Beach Diet focuses on learning about the source of carbohydrates instead of looking dispassionately at numbers, it can be an effective crash course on nutrition. According to Agatston, the diet will help people "learn to choose the right fats and the right carbs."

At the same time, without the restrictions that some other diet plans offer, followers of the South Beach Diet may fall off the wagon relatively quickly. The South Beach Diet won't appeal to anyone looking to quickly get a bikini-ready body; it's built for the long run, focusing almost as much on cardiovascular health as on weight loss. There also isn't very much instruction as to how exercise should be integrated with the diet plan.

Healthline Says

Generally, the South Beach Diet is pretty well-balanced and, for the right person, it could be effective in producing lifelong effects. If you can handle the tough first phase and then commit to really ridding your diet of "bad carbs," you will lose weight. However, if you're someone who needs stern guidelines, the South Beach Diet may not be right for you. There are no strict portion sizes, no calorie counting, and the snacking the diet recommends can easily get out of hand. In addition, although the diet does recommend regular exercise, there seems to be little focus on that aspect of the program, and the diet includes no incentives to do so. We think that exercise should always be an essential part of any weight loss program.

In terms of health worries, the first two weeks of the diet (phase 1) appear to be the most problematic. Losing 13 pounds in two weeks could be an indication that you're losing water or lean muscle weight, rather than fat. If you're going to follow the South Beach plan, make sure you stay hydrated. Also, if you consume fewer than 20 grams of carbs a day — the recommended amount during phase 1 — your body may develop ketoacidosis, which occurs when your body uses fat for energy instead of glucose. Ketoacidosis is a condition that primarily occurs in someone with poor insulin production, like in the case of type 1 diabetes. If left untreated, it can result in mental confusion, coma, or even death. Be extremely aware of how your body is responding to the diet during phase 1.

Because the South Beach Diet specifically seeks to lower your body's blood sugar level, it is essential that anyone who has a blood sugar-related medical condition, such as diabetes, take extra care before choosing the diet.

Always consult your healthcare provider before starting any weight loss program.

You Asked, We Answered

  • What are some more examples of “bad” and “good” carbs and fats?
  • Some examples of healthy carbs include sweet potatoes, beans, lentils, peas, oats, and fruit. Unhealthy carbs include chips, crackers, many cookies and desserts, sodas, sweetened drinks, pastries, and breads made with white flour. Healthy fats include avocado, nuts, seeds, wild salmon, and olive oil. Unhealthy fats include packaged foods made with hydrogenated fats, foods containing trans fats, fried foods, recycled oil, soybean oil, and corn oil. Consuming fatty red meats, sausage, and bacon regularly is also not advised.

    - Tara Gidus, MS, RD, CSSD, LD/N