Just Jeff covered the main stuff I was going to say, but another thing to keep in mind is that if you aren't maintaining your blood sugar levels(several small meals) your body will start releasing cortisol(stress related hormone) and one of the first actions that cortisol sets off is the burning of un-used muscle(in survival situations excess muscle is a liability).
1) muscle is easier to "burn" than your own fat
2) this means more energy to the muscles that need it
You'll notice that long distance hikers may look chiseled all over, but they are also experience a lot of atrophy every where that isn't getting used a lot relative to the prime movers... this will actually bring their resting metabolism down a good deal.
I'm still trying to put muscle back on from this summer