It's all about training your body to not want what is bad for you. Once you retrain your body you won't even miss it.
Instead of waking up thinking about garbage "cereal" for breakfast, the thought of nice hearty organic pasture raised eggs on some Ezekiel bread slathered thick with organic real butter and topped off by some berries and yogurt with your coffee or tea only being either plain or with nothing but heavy cream.
Instead of lusting after pasta you'll be thinking about how delicious the meat sauce with all that fresh delicious meat is, as it is poured over a bed of crisp vegetables, or enjoying cast iron pan roasted crispy chicken with a plain undressed salad of crunchy vegetables.
When you go to bed, you'll be thinking about some 95% chocolate squares or a nice square of real cheese or such.
Do it for a year and you won't even want to consider all the carb & sugar based treats you see at the store.