What Is the South Beach Diet?

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The South Beach Diet is one of the most popular weight loss programs of all time. The diet is divided into three phases during which people following the plan focus on eating lean protein, nutrient-rich carbohydrates, and healthy fats. An exercise program is also a key part of the South Beach Diet. 

Many consumers find the three-phase system easy to follow and quite effective, but not all experts agree that the South Beach Diet is a good approach to weight loss or overall health. This South Beach Diet summary will give you an overview of each phase and tips for following the program so you can decide if it will work for you. 

What Experts Say

“The South Beach diet is a low-carbohydrate, low-sugar weight loss diet. Foods are categorized into “allowed” and “avoid” and the focus is weight loss—things many experts agree can cause food fear, ignore individual needs, and put a focus on external factors rather than health.”
Willow Jarosh, MS, RD


The South Beach Diet was originally a diet plan outlined in a book by Arthur Agatston, MD. The doctor developed the plan in the 1990s to help his patients lose weight. The South Beach Diet: The Delicious, Doctor-Designed, Foolproof Plan for Fast and Healthy Weight Loss flew off shelves in 2003 when it was first published.  

Dr. Agatston noticed that patients on the Atkins diet were losing weight and abdominal fat. Being a cardiologist, he was concerned by the amount of saturated fat on Atkins, so he developed his own high-protein, low-carb diet that is lower in saturated fat. 

Since that time, the book has gone through several variations and changes, but the core of the eating plan has stayed the same.

The South Beach Diet is a low-carb, high-protein and low-sugar program. The diet is based in part on the glycemic Index, which ranks foods according to glycemic load. As you learn how to do the South Beach Diet, you learn how to choose healthier, lower sugar foods to keep you full and satisfied so you eat less and slim down.

How It Works

This diet focuses on a healthy balance between carbs, protein, and fat. More importantly, you are advised to consume high-quality carbohydrates, lean protein, and healthy fats. Foods with added sugars, like baked goods, sweets, and soft drinks are off limits. So if you are used to filling up on these foods, the diet may be hard to follow. 

Prepackaged South Beach Diet foods, such as shakes, snack bars and prepared breakfast, lunch, and dinner meals are available for consumers who sign up for the paid program. Many of these foods are similar to foods that you may feel uncomfortable giving up. But you'll eat them in smaller quantities if you buy the South Beach versions and the foods are prepared with fewer calories. 

The diet has three stages, known as phases, during which the proportion of carbohydrates is gradually increased, while the proportion of fats and protein are simultaneously decreased. The diet is comprised of a list of recommended foods such as lean meats, vegetables, and "good" (mostly monounsaturated) fats.

All three phases include specific allowable foods, meal plans, and recipes. Each phase also includes foods to avoid. 

South Beach Diet Phase 1 (also called 7-Day Reboot)

For most people, the most difficult part of the program is Phase 1. In some versions of the plan, this phase lasted for two weeks. However, current versions of the use a 7-day "reboot" instead of a two-week phase.

This first part of the plan is the most stringent of the three phases. It is when you will limit the most carbs from your daily diet, including fruit, bread, rice, potatoes, pasta, sugar, alcohol, and baked goods.

The theory behind this phase is that there is a switch inside us that affects the way our bodies react to the food we eat and makes us gain weight. When the switch is on, we crave foods that actually cause us to store fat. However, by following the specified plan, you can correct the way your body reacts to food. 

Many South Beach Diet fans swear that their cravings for sweets and other bad carbs virtually disappear during this reboot. For some, the first phase can be extended, but it is not meant to be a permanent way of eating. 

South Beach Diet Phase 2

During this phase, you can start adding in more foods, such as additional sources of carbohydrates, like beans and legumes.

During Phase 2, the calorie range and the macronutrient breakdown are almost the same as in Phase 1 but the number of calories allowed from saturated fats decreases to less than 10 percent of total calories. 

The exercise recommendation is to engage in at least 30 minutes of physical activity each day. Beginning in Phase 2 you can engage in more intense physical activity, if desired.

South Beach Diet Phase 3

Phase 3 is the final and least restrictive part of The South Beach Diet. Dr. Agatston says as long as you continue to follow some basic guidelines, the diet becomes your way of life and you'll continue to maintain your weight.

Pros and Cons

Like any diet, the South Beach Diet has its own set of positives and negatives. 

On the upside, the South Beach Diet is super simple and it encourages individual experimentation. When you sign up for the paid version of the program, you won’t have to do any guesswork about portion sizes, and whether or not you pay for the program, the allowed and not allowed foods are clearly outlined. 

On the other hand, the first portion of the South Beach Diet can seem extremely restrictive and potentially lead to disordered eating or yo-yo dieting down the road. Additionally, this diet promotes consumption of processed, packaged foods (the bars and shakes that come with the plan). The South Beach Diet may also not be structured enough in the later phases, which could result in weight regain for people who aren’t sure how to control portion sizes after phases 1 and 2. 

Common Myths and Questions

Like many diets, several myths surround the South Beach Diet. Here are some common myths, and the truth that dispels them. 

Myth: You can be successful on the South Beach Diet without exercise.

This is a loaded myth because it’s true, but it isn’t. Any diet — regardless of types of food, timing and supplements — can lead to weight loss as long as you’re in a calorie deficit. That is, you eat fewer calories than you burn. However, when you rely on diet only for weight loss, your progress will be slow at best. Adding in a few minutes of exercise each day can expedite your weight loss goals regardless of what diet you’re on.  

Myth: You can lose weight just by implementing the bars and shakes from South Beach Diet.

Many people believe that just replacing foods with the South Beach Diet official snacks and shakes will result in weight loss. Unfortunately, successful weight loss isn’t that easy: You must pay attention to your total caloric intake and make sure you’re burning more calories than you eat. While replacing full meals with bars and shakes may result in weight loss, once regular eating is implemented weight regain is likely to occur.

Myth: You’ll lose all the weight you need during Phase 1 of the South Beach Diet.

It’s common to use short, extremely restrictive periods as a sort of “crash course” for weight loss. However, it’s much more sustainable to lose weight slowly over time. Healthy, safe, and sustainable weight loss is generally 1-2 pounds per week. Extreme weight fluctuations are typically a result of water loss and sometimes muscle loss. Extreme weight fluctuations is typically a result of water loss and sometimes muscle.
Also, by severely restricting your food consumption for one week, you might set yourself up for a binge at the end of the week. If you don’t continue to monitor your intake, you’ll gain back all the weight you lost. 

How It Compares

The South Beach Diet has been compared to several diets, including other popular ones such as the Atkins Diet. The South Beach Diet differs from other low-carb diets in that it does not require cutting out carbohydrates entirely or even measuring intake. Here’s how it compares to some diets and the federal dietary guidelines. 

Atkins vs. South Beach Diet

The Atkins diet is another low-carbohydrate plan. The Atkins Diet was also developed by a doctor and has gone through many variations through the years. The South Beach Diet has been called a less-strict version of Atkins. Both Atkins and South Beach require you to go through a strict introductory phase. But during the later phases of South Beach, you are able to eat more carbohydrates and enjoy treats on occasion. Both the Atkins and South Beach Diet include maintenance programs for long-term health and well-being.

There are slight differences between the South Beach and the Atkins diet in the type of protein allowed on each plan. On the Atkins diet, cured meats that are higher in sodium (such as ham) are allowed but not recommended. On South Beach, consumers are advised to skip these meats entirely. Pork bacon is allowed on Atkins, while only turkey bacon is allowed on South Beach. Keep in mind that processed meats have been associated with overweight, obesity, and increased risk of heart disease and cancer. 

There are also slight differences in the types of dairy included on each plan. Atkins includes small portions of butter and heavy cream on their plan. While South Beach does not. Both diets recommend many full fat dairy products.

Keto vs. South Beach Diet

A keto diet is higher in fat and lower in protein than the South Beach diet. However, the introductory phase of the South Beach Diet is comparable in some ways to a ketogenic, or keto, diet. The difference is that the South Beach Diet becomes less strict as you work your way through the phases, allowing you to add in more carbohydrates. On a keto diet, however, the intention is to remain low-carb for the long haul. We still don't know the long-term effects of an extremely low carbohydrate diet. 

Federal Recommendations vs South Beach Diet

The first two phases of the South Beach Diet don’t match the federal dietary recommendations, which emphasize whole grains. However, the entire South Beach Diet emphasizes fiber-rich vegetables, fruits and lean protein, as well as minimal saturated fat and sugar. The South Beach Diet also outlines healthy exercise recommendations, which are close to the federal exercise recommendations for adults. 

A Word from Verywell

The first week of any new way of eating can be challenging. Know that there will be rough spots, especially as your body gets used to foods that weren't previously in your meal rotation as often, or cooked in that particular way, or ever. Give yourself compassion if you make inadvertent mistakes, and stay enthusiastic about your transformation. Remember that these nutritious foods are meant to improve your health and get you to your weight goals.. And If you have any pre-exisiting health conditions or are pregnant or nursing, this diet may not be right for you. Always consult with a healthcare provider before starting any diet plan.

11 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Laura Dolson
Laura Dolson is a health and food writer who develops low-carb and gluten-free recipes for home cooks.