Personally, I think it's a better idea to let yourself have semi-cheat snacks or meals a few times throughout the week. For example, when you are craving salt, have light popcorn. If you want something sweet, have a low-cal granola bar. There are many healthy alternatives that can help curb cravings and leave you not feeling guilty afterward.
If you really feel you just can't resist that bacon cheeseburger and cheese fries, allow yourself to eat the meal, but sip water after every bite. Allow your brain to realize it is full, and stop once you are satiated. A restaurant portion is almost always larger than what you need to feel full, so eat half of your plate. After all, our stomachs are only the size of a loose fist!
Healthy eating should be a lifestyle - don't think of it as a diet, just try to eat healthfully and have unhealthy treats in moderation.
Allowing yourself an entire day to 'cheat' could lead to a huge binge day which you will feel guilty about afterward. Do your best to take it one day at a time and allow yourself small treats every once in a while rather than scheduling an entire day where you stray from being healthy.
