South Beach diet

My sister recently over the past year or more lost a little over 100 lbs. She still goes to Weight Watchers and TOPS both, but she does her own diet. Someone had mentioned the South Beach diet, its much like the Atkins but it allows much more fruit and veggies. Since she has been at a plateau for several months, she decided to try this South Beach diet. She lost 9 pounds in 8 days. Her husband lost 7 pounds. My niece isn't talking. Anyone else try this one?