I did South Beach in my early 20s and lost almost 30 lbs. I found that after a while, i couldn't lose any more weight, even after going back into Phase 1 as a kick start.

I was very successful the first time around with IP, and so far am doing pretty well the second time around (i lost 42 lbs the first time and then went off protocol because of money and working full time, going to school full time and student teaching. No excuse, i know).

I did have some hair loss with the first round of IP, but i found that some TLC (scalp treatments, and extra hair skin and nail vitamins) really helped. I'm taking precautions now with my hair, and so far so good!