This is one of the recent diet plans promoted by cardiologist Arthur Agatston, in the year 2003. This diet has its origins from the glamorous city of Miami, thus also called as modified low-carbohydrate diet. It emphasizes eating high-fiber, low-glycemic carbohydrates, unsaturated fats, and lean protein, and high-fiber foods making the diet nutrient dense.

Though it is a low-carbohydrate diet but the carbohydrate content is not as low as typical low-carbohydrate diet. At least 140 grams of carbohydrate is allowed for consumption unlike typical low-carbohydrate diet allowing up to 100 grams. The foods with low glycemic index are more likely to be included than the high glycemic index foods. Evidences have shown that high glycemic foods tend to increase your blood sugar faster, higher and longer than do foods with a lower index, moreover high blood sugar boosts the appetite, thus predisposing to over-eating, obesity, diabetes and cardiovascular diseases.

The South Beach Diet plan can be followed in a step-wise pattern. It has three phases: The first phase is designed to reduce the cravings of high sugar and refined starched foods, which kick starts the weight loss. It is followed by a phase wherein whole-grain foods are added to achieve the target weight. The final phase includes maintenance phase which includes lifestyle modifications.
This is one such diet which can be followed through out. As there is no calorie count or prohibited foods!! 

-Koya Satyasri