I absolutely second Sonerila's suggestions. I lost 50 pounds this way over about a year (no refined flour or sugar-sweetened stuff and more nuts, fruits, honey, vegetables, brown rice, whole wheat, oatmeal). It almost seems like it takes your body more calories to digest this stuff so you're not getting hungry as you switch over.

If you had suggested this to me about three years ago I would have said, "No way, life's too short to deprive myself" but I feel so much better, and it's so easy to follow. Add that type of diet to cycling and I think you'll see good results. Heck, I'm almost not afraid of lycra now!