I lost 30 lbs and got down to 172 lbs by running regularly for several months (at peak was running 60 miles a week). The bad thing about that is that when cold weather or breaks occurred it was hard to get back on the train.
I then went back up to 180 recently but started eating mainly just fruits and vegetables with a little meat, almost no carbs, and no sweets or sodas, sugar or milk in my coffee, etc and was back down to 175 yesterday. I still haven't gotten back to exercising regularly (even though I still have a gym membership) but plan to, but I'm glad I'm finally tackling my diet because even when I was running 60 miles a week I still wasn't eating very well, probably because I was still burning a lot of it off.
Now if I can just maintain my diet and get exercise back into the picture I should be able to get down to the 160s and build muscle mass.