We are all human, meaning we are all not perfect. It is entirely possible to wind up losing control of your regimented exercise and diet plan, making bad eating choices on a given day. Here's how to recover should that happen to you (remember don't starve yourself as a quick way of getting back on track - that will only make the situation worse):
http://www.huffingtonpost.com/self/diet-and-nutrition_b_4683091.html
http://www.huffingtonpost.com/self/diet-and-nutrition_b_4683091.html