The most freeing thing any of my teachers ever said to me is "There is no right." That was Candace Silvers. I looked up to her and sat at her feet (metaphorically) for years. Once she took away the concept of trying to be "right" I was far more creative, playful and allowing. I had been raised in the do it right mindset that had me gasping for air. You need air to live.
Most people think there is a right way to eat. They want to believe they are doing it right or they enjoy cheating because it gives them a thrill to be "bad". Remember Michael Jackson's "Thriller"? He got that being bad was cool. The only problem with this is when you are so enamored with being cool and trying to live above consequences, you are still subject to things like gravity or physical reactions to what you eat.
I had built in moderators. My skin goes crazy and my health immediately takes a hit when I try to goof off and eat all sorts of crazy things. It's pretty simple to stop doing things that hurt when they consistently and blatantly cause suffering with a specific action. It takes a little more reminding when the consequences are more subtle and sneak up on you. Like a belly that has grown or pants that just don't zip up anymore.
Candace also gave us tools. She has a great tools tape and taught us specific things that we could do to make our acting scenes pop or recognize human behavior and shift to have a better life. It is the same with food. You learn how the foods work. You stop guessing and start living and the guidelines help to make your life more full, fun and free. Suffering isn't cool but having healthy fun is far better than cheating or sneaking. Letting go of doing things perfectly is fabulously freeing.