Living a healthy life is all about balance. You have to learn how to walk a line between self-denial and self-indulgence. It's the middle ground between the two that offers the best foundation on which to build your new life. Denying yourself little pleasures such as the occasional glass of wine or chocolate truffle will only make you feel deprived, frustrated, and ultimately hopeless about maintaining your discipline. A temptation is a lot less powerful if it isn't totally forbidden. This is where moderation comes in.
I will never be able to give up all the edible goodies life has to offer, but by practicing moderation I've found a solution to my weaknesses that I can live with every day. There's room for all foods, no matter how "bad" they are; it's just a matter of being conscious and careful of how often you eat them and how much. It's fine to have a piece of cake now and then — just not every day, and not the whole cake.
I can already hear what you're thinking: "If I eat a little bit, I'll want it all." We all have at least one food that we truly can't eat a little of without going overboard. Mine is ice cream. If you know that a particular food has that kind of trigger effect on you, try choosing an alternative. I will often have a few bites of organic dark chocolate instead of ice cream so that my sweet tooth will be satisfied but I won't end up with an empty ice cream carton in my hands. If your weakness is potato chips, try having some air-popped popcorn as a snack instead. Trust me — in time you can adapt so that small amounts of "cheat" foods will not set you off on a binge.