About 7 years ago my DH wanted to lose 10 lbs before we went on a vacation. We had about 3 months. It was September, so the cycling season was winding down by the end of October. In order to support him, I did the South Beach diet with him. I agree; the initial phase was very difficult to do while cycling/running/hiking. It was only 2 weeks, but we did "cheat" a bit and add in some whole wheat bread and cereal on the weekends when we were doing longer rides. The other phases were really not much different from the way I already ate, so for me it was more a question of adding more protein. He easily lost the 10 lbs. and I think I lost 5 (I really didn't need to lose it).