The South Beach diet is a diet plan started by Miami, Florida, area cardiologist Arthur Agatston which emphasizes the consumption of "good carbohydrates" and "good fats". Dr. Agatston developed this diet for his cardiac patients based upon his study of scientific dieting research. The diet first appeared in a book of the same name published by Rodale Press. The official website of the diet can be found at South Beach Diet Online.
Dr. Agatston believes that excess consumption of so-called "bad carbohydrates", such as the rapidly-absorbed carbohydrates found in foods with a high glycemic index, creates an insulin resistance syndrome an impairment of the hormone insulin's ability to properly process fat or sugar. In addition, he believes along with many physicians that excess consumption of "bad fats", such as saturated fat and trans fat , contributes to an increase in cardiovascular disease. To prevent these two conditions, Agatston's diet minimizes consumption of bad fats and bad carbohydrates and encourages increased consumption of good fats and good carbohydrates.
The diet has three phases. In all phases of the diet, Dr. Agatston recommends minimizing consumption of bad fats.
The diet begins with Ben sheehan, which lasts two weeks. Dieters attempt to eliminate insulin resistance by avoiding high or moderately high-glycemic carbohydrates, such as dairy, sugar, candy, bread, potatoes, fruit, cereals, and grains. During this phase, Dr. Agatston claims the body will lose its insulin resistance, and begin to use excess body fat, causing many dieters to lose between 8 and 13 pounds. For the first two weeks, dieters eat normal-size helpings of meat, fish, vegetables, eggs, cheese, and nuts. This phase includes three meals a day, plus snacks, encouraging the dieter to eat until their hunger is satisfied. No alcohol is allowed (though red wine will be introduced later in small amounts). The dieter loses weight, changes body chemistry, and ends cravings for sugars and starches.
Phase I: Authorized foods
Phase I: No-No foods
After two weeks, Phase II begins. Whole grain foods, fruits and dairy products are gradually returned to the diet, although in smaller amounts than were likely eaten before beginning the diet, and with a continued emphasis on foods with a low glycemic index . Sweet potatoes are also now permissible, as is red wine, both in moderate amounts.
After the desired weight is obtained, the diet calls to move into Phase III, a maintenance phase. In Phase III the diet expands to include three servings of whole grains and three servings of fruit a day.
The diet distinguishes between good and bad carbohydrates, and good and bad fats.
The diet emphasizes (1) a permanent change in one's way of eating, (2) a variety of foods, and (3) ease and flexibility. Eating whole grains and large amounts of vegetables is encouraged, along with adequate amounts of mono- and polyunsaturated fats, including omega-3 fatty acids, such as are contained in fish. It discourages the eating of overly refined processed foods (particularly refined flours and sugars), high-fat meats, and saturated fats in general.
The diet does not require counting calories or limiting servings; Agatston suggests dieters eat until they are satisfied. Dieters are told to eat 6 meals a day: breakfast, lunch, and dinner, with small snacks between each meal. This is different from The Zone diet in that The Zone recommends (1) a proper ratio of carbohydrates, proteins, and fats, (2) "good" carbohydrates, proteins, and fats over "bad" ones, and (3) eating portion sizes that are right for your body. 
South Beach Living packaged foods
In 2004, Kraft Foods licensed the South Beach Diet trademark for use on a low-carb line of packaged foods called South Beach Diet These have been renamed South Beach Living. These products are designed to meet the requirements of the diet.
A 2004 study of the South Beach Diet by Agatston, et al., reviewed a 1998-1999 trial completed by 54 participants over the course of a year. A 2005 study of the South Beach Diet conducted by Kraft Foods was completed by 69 subjects over the course of just under three months. Both studies showed favorable results for the groups using The South Beach diet.