I lost about 40 lbs (from 150-111 lbs) on weightwatchers several years ago. I started cycling after a 2 month plateau (after I lost the first 13). I have gained back about 10 pounds over the last 3 years, which really frustrates me, because I ride 80-100+ miles a week. If I don't track, my weight inches up again.
I've found it's sometimes hard to balance the eating/ exercise. I get hungry the day after a long ride, but of course then I'm not using up the calories so it's frustrating.
I think weightwatchers can be a good and effective program however. Good luck with whatever you choose to do, and good for you in making a choice to become more healthy and fit.
2016 Specialized Ruby Comp disc - Ruby Expert ti 155
2010 Surly Long Haul Trucker - Jett 143