I've been commuting for 6 years now and so far I don't think I've lost a pound, but I'm OK with that. I'm between 175 and 185 depending on various factors, at 5'11". I started running when I hit 195, got back down to about 185, got myself a stress fracture and switched to riding. I wouldn't mind lowering the range by 10 pounds, but I'm OK with where I am.

My big problem is cutting out HFCS - not drinking the two sodas a day that I'm pretty much addicted to would probably make the 10 pound difference.

Recent studies indicate that the body doesn't absorb fat much without carbohydrates also, for what it's worth.