Could this low-carb diet give you an edge in losing weight? Help you keep weight off permanently? Here's what you need to know.By Mayo Clinic Staff
The South Beach Diet is a popular commercial weight-loss diet created in 2003 by cardiologist Arthur Agatston, M.D., and first outlined in the best-selling book "The South Beach Diet: The Delicious, Doctor-Designed, Foolproof Plan for Fast and Healthy Weight Loss."
The South Beach Diet, which is named after a glamorous area of Miami, is sometimes called a modified low-carbohydrate diet. The South Beach Diet is lower in carbs (carbohydrates) and higher in protein and healthy fats than is a typical eating plan. But it's not a strict low-carb diet.
There is also a keto (ketogenic) version of the South Beach diet. Ketogenic diets include very few carbs. The goal of a ketogenic diet is to force the body to use fat for energy instead of carbohydrates or protein.
The purpose of the South Beach Diet is to change the overall balance of the foods you eat to encourage weight loss and a healthy lifestyle. The South Beach Diet says it's a healthy way of eating whether you want to lose weight or not.
Why you might follow the South Beach Diet
You might choose to follow the South Beach Diet because you:
- Enjoy the types and amounts of food featured in the diet
- Want a diet that restricts certain carbs and fats to help you lose weight
- Want to change your overall eating habits
- Want a diet you can stick with for life
- Like the related South Beach Diet products, such as cookbooks and diet foods
Check with your doctor or dietitian before starting any weight-loss diet, especially if you have any health concerns.
The South Beach Diet says that its balance of complex carbs, lean protein and healthy fats makes it a nutrient-dense, fiber-rich diet that you can follow for a lifetime of healthy eating. Food sources of complex carbs, or so-called good carbs, include fruit, vegetables, whole grains, beans and legumes. Simple carbs, or "bad" carbs, include sugar, syrup and baked goods made from refined white flour.
The South Beach Diet also teaches you about the different kinds of dietary fats and encourages you to limit unhealthy fats while eating more foods with healthier monounsaturated fats. The South Beach Diet emphasizes the benefits of fiber and whole grains and encourages you to include fruits and vegetables in your eating plan.
The South Beach Diet is lower in carbohydrates than is a typical eating plan, but not as low as a strict low-carb diet. On a typical eating plan, about 45% to 65% of your daily calories come from carbohydrates. Based on a 2,000-calorie-a-day diet, this amounts to about 225 to 325 grams of carbohydrates a day.
In the final maintenance phase of the South Beach Diet, you can get as much as 28% of your daily calories from carbohydrates, or about 140 grams of carbohydrates a day. A strict low-carb diet might restrict your carb intake to as little as 20 to 100 grams a day. The keto version of the South Beach diet limits carbs to 40 grams a day during phase 1, and 50 grams during phase 2.
The South Beach Diet has evolved over time and now recommends exercise as an important part of your lifestyle. The South Beach Diet says that regular exercise will boost your metabolism and help prevent weight-loss plateaus.
Phases of the South Beach Diet
The South Beach Diet has three phases:
- Phase 1. This two-week phase is designed to eliminate cravings for foods high in sugar and refined starches to jump-start weight loss. You cut out almost all carbohydrates from your diet, including pasta, rice, bread and fruit. You can't drink fruit juice or any alcohol. You focus on eating lean protein, such as seafood, skinless poultry, lean beef and soy products. You can also eat high-fiber vegetables, low-fat dairy and foods with healthy, unsaturated fats, including avocados, nuts and seeds.
- Phase 2. This is a long-term weight-loss phase. You begin adding back some of the foods that were prohibited in phase 1, such as whole-grain breads, whole-wheat pasta, brown rice, fruits and more vegetables. You stay in this phase until you reach your goal weight.
- Phase 3. This is a maintenance phase meant to be a healthy way to eat for life. You continue to follow the lifestyle principles you learned in the two previous phases. You can eat all types of foods in moderation.
A typical day's menu on the South Beach Diet
Here's a look at what you might eat during a typical day in phase 1 of the South Beach Diet:
- Breakfast. Breakfast might be an omelet with smoked salmon or baked eggs with spinach and ham, along with a cup of coffee or tea.
- Lunch. Lunch might be a vegetable salad with scallops or shrimp, along with iced tea or sparkling water.
- Dinner. Dinner may feature grilled tuna or pork paired with grilled vegetables and a salad.
- Dessert. The diet encourages you to enjoy a dessert, such as a ricotta cheesecake or chilled espresso custard, even in phase 1.
- Snacks. You can enjoy snacks during the day, too, such as a Muenster cheese and turkey roll-up or roasted chickpeas.
The South Beach Diet says that you'll lose 8 to 13 pounds (3.6 to 5.9 kilograms) in the two-week period that you're in phase 1. It also says that most of the weight will be shed from your midsection. In phase 2, it says that you'll likely lose 1 to 2 pounds (0.5 to 1 kilogram) a week.
Most people can lose weight on almost any diet, especially in the short term. Most important to weight loss is how many calories you take in and how many calories you burn off. A weight loss of 1 to 2 pounds a week is the typical recommendation. Although it may seem slow, it's a pace that's more likely to help you maintain your weight loss permanently.
Losing a large amount of weight rapidly could indicate that you're losing water weight or lean tissue, rather than fat. In some situations, however, faster weight loss can be safe if it's done in a healthy way. For example, some diets include an initiation phase to help you jump-start your weight loss, including the South Beach Diet and the Mayo Clinic Diet.
The South Beach Diet, while mainly directed at weight loss, may promote certain healthy changes. Research shows that following a long-term eating plan that's rich in healthy carbohydrates and dietary fats, such as whole grains, unsaturated fats, vegetables and fruits, can improve your health. For example, eating a lower carbohydrate diet with healthy fats may improve your blood cholesterol levels.
The South Beach Diet is generally safe if you follow it as outlined in official South Beach Diet books and websites. However, if you severely restrict your carbohydrates, you may experience problems from ketosis. Ketosis occurs when you don't have enough sugar (glucose) for energy, so your body breaks down stored fat, causing ketones to build up in your body. Side effects from ketosis can include nausea, headache, mental fatigue and bad breath, and sometimes dehydration and dizziness.
April 25, 2020
- Agatston AS. The South Beach Diet: The Delicious, Doctor-Designed, Foolproof Plan for Fast and Healthy Weight Loss. Rodale; 2003.
- Joshi S, et al. The ketogenic diet for obesity and diabetes — Enthusiasm outpaces evidence. JAMA Internal Medicine. 2019; doi:10.1001/jamainternmed.2019.2633.
- South Beach Diet online. https://www.southbeachdiet.com. Accessed April 1, 2020.
- Carbohydrate counting & diabetes. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/diabetes/overview/diet-eating-physical-activity/carbohydrate-counting. Accessed March 15, 2017.
- Brouns F. Overweight and diabetes prevention: Is a low-carbohydrate-high-fat diet recommendable? European Journal of Nutrition. 2018; doi:10.1007/s00394-018-1636-y.
- Freire R. Scientific evidence of diets for weight loss: Different macronutrient composition, intermittent fasting, and popular diets. Nutrition. 2020; doi:10.1016/j.nut.2019.07.001.
- Bray GA. Dietary approaches for obesity. https://www.uptodate.com/contents/search. Accessed April 1, 2020.
- Ashtary-Larky D, et al. Rapid weight loss vs. slow weight loss: which is more effective on body composition and metabolic risk factors? International Journal of Endocrinology and Metabolism. 2017; doi:10.5812/ijem.13249.
- Hensrud DD, et al. Lose it! In: The Mayo Clinic Diet. 2nd ed. Mayo Clinic; 2017.
- Atallah R, et al. Long-term effects of 4 popular diets on weight loss and cardiovascular risk factors. Circulation: Cardiovascular Quality and Outcomes. Circulation: Cardiovascular Quality and Outcomes. 2014; doi:10.1161/CIRCOUTCOMES.113.000723.
- Hall KD, et al. Low-carbohydrate diets for the treatment of obesity and type 2 diabetes. Current Opinion in Nutrition and Metabolic Care. 2018; doi:10.1097/MCO.0000000000000470.
- DKA (ketoacidosis) and ketones. American Diabetes Association. https://www.diabetes.org/diabetes/complications/dka-ketoacidosis-ketones. Accessed April 1, 2020.