Ok, in response to the increase in discussion of slip-ups, I submit the following, pasted directly from Dr. Hussman's website:
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The goal of this is to have a fitness program you can live with. If you find that you get into guilty self-destructive binges after you eat some kind of "fun food," then it's much better to include a specific and limited amount of fun food as part of your written nutrition plan for each day (but no more than 5-10% of your total daily calories). It's not the cookie that will throw your program off, but guilt, "all-or-nothing" thinking, and self-abuse that says "I ate the cookie! I've got no willpower! I'm a loser! I've ruined my whole day with that one cookie! It's a cheat day now! I'll never succeed at this!" followed by a self-destructive binge in which you rapidly eat 20 more cookies. This is called disinhibition - where you drop all the rules and say "Ah, what the heck!" Don't fall into this. Remember: you're always in control. You're never going to accidentally eat a cookie. So if you're about to eat one and no other alternative will do, at least realize it's a choice. Enjoy that choice, and then get on with your program. Work it into your plan, so that you'll eat a little less later today, or a little less tomorrow, to make up that tiny bit of ground. Let me say that again: if you eat something you feel is a "cheat", realize the choice you're making beforehand, and if you choose to go ahead, at least enjoy it, and then get back to work. Don't be a wuss and nibble off little corners of a 12-inch cake until the whole thing is gone. And don't turn a minor indiscretion into a self-destructive binge.
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Hope this helps!