The South Beach Diet Plan requires a severe change in lifestyle. The diet puts a serious restriction on carbs especially in the first phase, but even throughout the second and third phase carbs are still restricted. This diet means that you will always have to watch how many carbs you take in. This diet is a lifetime plan and not just a diet you can follow for a couple of weeks. The first phase is a bit more difficult than the second or third phase. The second and third phase are a little less strict as far as carbs and sweets go.