The human body is a semi-batch (semicontinuous) process.
There is no 300 Calories - 3800 Calories = 1 lbs of weight lost, as the average cardio bunny, hovering over the algorithm on the treadmill, and scrutinizing the nutrition facts of her post workout Snickers bar would like to think.
The body is desparate, and utilizes calories instantaneously. If it didn't, you'd be dead. What's this mean? You're constantly burning fat. When you're running, when your walking, when your sitting on your ass eating chocolate cake, so long as you're living and breathing you are burning fat. You are also burning carbs and proteins as well.....CONSTANTLY!!!!!!! Needless to say, if you are consuming more calories than you are expending, some of those get put into a savings account we often call a "gut". The only means to obtain success through any diet is to find a balance between income and expendature, and good ol' Le Chatelier will take care of the rest.
The question now becomes, what is a "cheat meal"? The body treats calories like people treat money. If you're freaking loaded with cash, you tend to throw it around more because you can afford it. If you're below the poverty rate (and not a drug addict), you tend to try and be more conservative with your money, as you don't have as much to throw around.
The human body is the same way. When you're constantly working in a deficit, the body doesn't have as many calories to throw around as it pleases, and starts to get more conservative with calorie expendature. If you've ever met someone who's been anorexic for a long period of time, she's usually bundled up in warm clothes (even if it's not cold out). Why? Her body has been under such a deficit for so long that (to go along with the $ analogy) she's "on welfare, and can't afford to pay the heating bill."
Anyhow, the main point that I am trying to stress is that they human body is NOT a batch process. You cannot simply cut a finite amount of Calories, extrapolate that over an extended period of time, and expect everything to be all hunky dorey.