I don't know if what I found on another SB board will help explain the Phase of the south beach,but here they are.
Explaining the Phases of South Beach
Phase 1: The Strict Phase – For the first two weeks, eat normal-size helpings of meat, fish, poultry, vegetables, eggs, cheese, nuts, dairy, good fats, and more. The Phase 1 Foods To Enjoy list is extensive - this list is the foundation of your healthy food choices for life and doesn't change. Eat three meals a day, plus snacks, to keep your blood sugar levels consistent throughout the day. Eat until your hunger is satisfied. Desserts are allowed on this phase, including no-sugar-added Fudgsicles! Cravings for sugars and starches diminish and even disappear. Phase 1 is not meant to be used for more than two weeks.
Phase 2: The Weight-Loss Phase – Gradually reintroduce more “good” carbs into your diet from the Phase 2 Foods To Enjoy list, like fruits, whole-grain bread, high-fiber low-sugar cereal, whole-wheat pasta, brown rice and sweet potatoes. You're now eating a nutritious, well-balanced diet from both the Phase 1 and Phase 2 Foods To Enjoy lists. Learn to avoid the carbs that increase your blood sugar and make you gain weight. Typically, this phase allows for a weight loss of 1/2 - 2 pounds per week until you reach your ideal weight. Eating the right foods regularly thoughout the day helps rev up metabolism and makes you a fuel-burning machine. You'll have energy to spare. Exercise is highly encouraged and will increase metabolism, too. Eat treats while losing weight, such as SBD-friendly peanut butter cookies, sugar-free chocolate pudding and homemade muffins!
Phase 3: The Maintenance Phase – By the time the final phase of the diet is reached, blood chemistry is significantly improved (cholesterol and triglycerides) and there is a long-term benefit to the cardiovascular system. A condition called pre-diabetes, a fast-growing affliction among Americans, can be reversed. Continue to eat normal portions of healthy foods. Indulgences are allowed and aren’t considered “cheating”, because South Beach was designed to be a way of eating, for life. However, by this phase, an awareness of how foods affect the body has developed, and we know how to quickly get back on track after indulging. Many South Beachers experience a real change in their tastes for food over time, and no longer crave many of their old comfort foods the way they once did.