Hi, JessAus. I don't know much about the South Beach Diet. Yes, I think it is American.

Dr. Atkins' plan increases carbs as one gets closer to goal. It's only the Induction (beginning stage) that is very low carb.

There are other plans which are not so low. Barry Groves' Eat Fat and Get Thin.
Dr. Wolfgang Lutz' Life Without Bread.
Dr. Jan Kwasniewski's Optimal Diet

I don't know of any active threads for those plans just now.

Best wishes to you.