The South Beach diet, developed by Miami, Florida-area cardiologist Arthur Agatston, emphasizes the consumption of "good carbs" 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 South Beach diet is often incorrectly compared to the Atkins diet (see Atkins Nutritional Approach), which is predominantly a low-carbohydrate diet.
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 most 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 carbs and encourages increased consumption of good fats and good carbs.
The diet has three phases. In all phases of the diet, Dr. Agatston recommends minimizing consumption of bad fats. In Phase I, lasting two weeks, dieters attempt to eliminate insulin resistance by avoiding high or moderately high-glycemic carbs, such as sugar, candy, bread, potatoes, fruit, cereals, and grains. During this phase, Dr. Agatston says the body will lose its insulin resistance, and begin to use excess body fat, causing the dieter to lose between 8 and 13 pounds.
After two weeks, Phase II begins. Whole grain foods and fruits 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. When the dieter reaches the desired weight, Phase III begins. 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.
§ Good carbs are high in fiber or high in good fats, and have a low glycemic index, that is, they are digested and absorbed slowly. Other preferred carbohydrates are those with more nutritional value than the alternatives. For instance, brown rice is allowed in moderation, but white rice is discouraged. When eating any carbohydrates, Dr. Agatston recommends also eating fiber or fat to slow digestion of the carbohydrates.
§ Good fats are polyunsaturated and monounsaturated fats, especially those with omega-3 fatty acids. Saturated and trans fats are 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 you eat until you are satisfied. Dieters are told to eat 6 meals a day: breakfast, lunch, and dinner, with small snacks between each meal.
In 2004, Kraft Foods licensed the South Beach Diet trademark for use on a line of packaged foods that would be 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.