Dr. Arthur Agatston, the man behind the South Beach Diet, says excess consumption of "bad carbohydrates"such as those that are rapidly-absorbed carbohydrates have a high blood glucose level and that creates an impairment of the hormone insulin's ability to properly process fat or sugar. Futhermore, he states that excess consumption of "bad fats" like the saturated fat and trans fat are responsible for an increase in cardiovascular disease. So in order to avoid this, the Doctor's diet reduces consumption of bad fats and bad carbs and advises increased consumption of good fats and good carbs.

The three phased Diet Plans suggest the minimal consumption of bad fats. Phase I which lasts for two weeks is an attempt for dieters to remove the insulin resistance by abstaining from high or moderately high-glycemic carbs like sugar, candy, bread, potatoes, fruit, cereals, and grains. With this Phase of the diet, Dr. Agatston says the body loses its insulin resistance and starts to use up the extra body fat enabling the dieter to lose between 8 and 13 pounds.

Now, Phase II starts. Whole grain foods and fruits are slowly accepted into the diet, though in small amounts, with a continuous emphasis on foods with a low glycemic index. Once the dieter has achieved the desired weight, Phase III starts. The Phase III diet allows three servings of whole grains and three servings of fruit a day.

The Diet shows that:

• Good carbs are high in fiber or in good fats, and have a low glycemic index, that is, they are digested and absorbed easily and at a slower pace. Other preferrences of carbohydrates are those which have more nutritional value. For instance, brown rice is allowed in moderation, but white rice is not. When eating any carbohydrates, Dr. Agatston also advices eating fiber or fat to slow down the digestion of the carbohydrates.
• Good fats are polyunsaturated as well as monounsaturated fats especially those that contain omega-3 fatty acids whereas the saturated and trans fats are the bad fats.

It emphasises on changing your diet plan completely and permanently, adds a large number of foods and all this is done in an easy and flexible manner. It also gives great importance to good nutrition which includes whole grains and adds a large amount of vegetables which are neccessary along with sufficient amounts of mono- and polyunsaturated fats.Omega-3 fatty acids, like fish, are to be included. The foods to be avoided are eating overly refined processed foods (especially refined flours and sugars), high-fat meats, and saturated fats.

However, there is no requirement to count your calories or limit your intake of food. Dieters of the South Beach Diet are told to eat upto 6 meals a day i.e. breakfast, lunch and dinner with small snacks in between each meal.