The South Beach Diet weight loss plan is a three phase diet plan which, rather than banning carbohydrates and fats altogether, seeks to educate dieters about which are the right carbohydrates and fats to eat. If someone eats refined sugars and simple carbohydrates (eg baked goods) they are absorbed quickly into the bloodstream, raising blood sugar and soon resulting in hunger again. However, complex carbohydrates such as grains, cereals and so on are good in that they are digested slowly and give the fullness factor which prevents immediate cravings for more to eat.

Phase one of the South Beach Diet weight loss plan lasts for two weeks and is incredibly strict. There is no carbohydrate allowed i.e. bread, cereals, baked goods, potatoes, yams and even carrots are prohibited, although some fats are permissible such as olive oil and some hard cheeses, for example cheddar. A dieter who follows this plan rigorously could lose as much as 1 stone (14 lbs, 6.4 kg) in this initial two week phase.

Phase two gradually reintroduces some of the forbidden foods such as wholegrain bread and cereal and should be followed until the weight loss goal has been achieved and serves as a retraining phase. In other words, the dieter gets used to eating good carbs and good fats and snacking on fruit rather than cakes and biscuits.

Phase three is the maintenance phase. The dieter has reached his or her goal in terms of weight and that's exactly where they want to keep it. This is the adoption of a lifestyle change whereby, although the occasional cake or bag of crisps is not prohibited, it should be a very rare treat. Some people find that they don't even enjoy sweet or processed foods any more and are much happier snacking on a carrot stick or piece of celery.

Many people find that the South Beach Diet weight loss plan really does work for them, especially if they can get through the first two weeks, which is a real baptism of fire for those who have previously lived on junk food.