The South Beach diet is just a heart-friendly version of the Atkins diet. Both South Beach and Atkins diets restrict carbohydrates -- carbs, as diet dilettantes like to say. True, "good carbs" are allowed. But South Beach dieters must say goodbye to potatoes, fruit, bread, cereal, rice, pasta, beets, carrots, and corn for the first two weeks. After that, most of these foods remain strongly discouraged. The difference, really, boils down to two things: 1.Fats. The South Beach diet bans unhealthy fats but strongly promotes healthy ones. 2.Carbs. The South Beach diet doesn't count grams of carbs. The Atkins diet seeks to change a person from a sugar-burning machine into a fat-burning machine. The South Beach diet looks at how much sugar is in a carb. Low-sugar carbs -- those with a low glycemic index (they don't cause the blood sugar levels to rise and fall as quickly) -- are good.
http://www.webmd.com/content/pages/15/96038.htm Hope this helps.