I recently heard somebody say they were a bad person. They based their assessment on choices they may have made they thought were perhaps not the best.
If you ever find yourself thinking something like that, STOP IT. This is not necessarily related to diet and exercise, but to self esteem in general (which of course is intricately tied in to weight issues, so maybe it is related, but I digress...)
We have all made bad choices. I know I've made a ton of them in my life. But I refuse to let them define who I am as a person. If you make bad choices and let them define you as a bad person, you start to believe you aren't worth the good choices. So you keep making bad choices. Vicious, draining and totally self defeating cycle. You keep opting for the bad choices. You can apply that across the board: food, relationships, whatever it is.
If you recognize that you're making a choice you aren't really comfortable with yet you keep making it over and over and over, ask yourself something. What is it I'm hoping __________(fill in the blank)will do for me? Particularly emotionally. Chances are, it's not really giving you what you're hoping it will. You keep making that same choice because you don't want to face down what it is that's really the issue. But even then, that does NOT make you a bad person. (Of course we're not talking about mass murderers, child molesters and serial rapists here...)
We have to deal with our issues. Let's take food, for example. If you have used food in the past as a way to try to deal with problems, and you suddenly take that option away but haven't dealt with the issues, chances are you'll just find something else. In fact, there have been studies done on people with food addictions who had weight loss surgeries. A good many of them simply traded in the food addiction for another addiction (sex, shopping, gambling.) We are emotional creatures. Our emotions drive so much of what we do. We have to get in touch with them, even the hard ones that scare the crap out of us.
But please, please, please...don't let bad choices make you believe you're a bad person. Self-esteem is a nebulous (and for me lately, rather a capricious) thing. Don't just hand it away! Fight for it!