If you're following a relatively controlled diet, then no doubt you will already be familiar with the concept of "cheat day".
The theory is that having conditioned the body into being used to high quality food (lots of nutrients and protein, minimal processed carbohydrates, gluten or refined sugars) you will actually get improved results/benefits by occasionally shocking the body (specifically your digestive system) with a big dose of food that you normally wouldn't eat.
There are of course various interpretations of what is actually allowed on a "cheat day".
A strict interpretation would be that "cheating" means allowing yourself a small bowl of brown rice once a week. While probably correct, and if you're working towards a photo-shoot for the cover of Men's Health, probably advisable, but to be honest not a lot of fun and if you are being that strict with yourself for a sustained period of time then it may actually make it harder for you to stick with the diet (ie. in a couple of weeks you'll spectacularly give in to all of your cravings and undo all of your hard work).
I tend to favour a "dirty Chinese" once a week (Sunday night after a movie is perfect). You know it's not good for you, but it's generally rice-based (which is the easiest form of gluten for your body to cope with) - plus, it's tasty and social.
Cheat Day. Get on board.