There's actually a school of thought that promotes the use of "cheat meals" to increase your fat loss efforts and keep your metabolic rate higher. This is basically planned overeating at certain times while keeping overall weekly calorie intake where it needs to be for fat loss.
The thinking is along these lines : restricting calories for too long causes your body to fight back and reduce your metabolic rate. This is a simple survival tactic because your body thinks a possible famine is on the way so it needs to hold on to your body fat and start conserving calories.
To overcome this effect and keep losing fat, you need to fool your body into thinking that plenty food is available again, and this in turn will pump up your metabolic rate again.
It's all apparently got to do with leptin levels in your body and how "strategically overeating" influences these levels. From what I've read it seems that one day a week pigging out actually contributes to fat loss
Try stay away from trans fats and high sugar content meals though

unfortunately for me my day off appears to have been yesterday (... and sunday ... and saturday )