Loads of people, all the time, say that they won't eat something - a burger, some crisps, a bar of chocolate - because it's "bad for you". Wrong. Eating 12 burgers, 20 bags of crisps, or 40 cubic feet of chocolate is bad for you. A little bit? No. Nothing - apart from perhaps lead and cyanide - is bad for you if you eat it sparingly. Indeed, I go further: all those foods are good for you. They contain stuff your body needs, stuff it'll struggle to get if you only eat salads and low fat rice crackers. And let's, face it, who likes salads?
What I'm saying is that - unless you have a serious medical condition - don't bother dieting to lose weight. Just go to the gym. Sure, maybe you shouldn't eat so much chocolate or crisps or burgers, but don't cut everything nice out of your diet because people say it's "bad for you". To borrow a phrase from Woody Allen:
"I can live to be hundred if I give up all the things that make me want to live to be a hundred."