Mountain Bike Riders, Question

Thanks for the responses. Keep em coming.
I was a body builder when I was younger, and I have a very large bone structure. At 210lb, I had less then 7% body fat. I doubt I can get back to that, but if I can get in the ballpark, I'd be happy. I did join the local gym this week, and I changed jobs which should help me stay away from fast food every day.