As opposed to 'giving up ' / 'quitting', my other half and I have instead progressively shifted towards a quality over quantity approach of a number of things, including alcohol and sweet things. The result has been a reduction in the volume consumed and the return to valuing them as special when we do have them.
Chocolate should never be given up IMO (we're the only planet we know of that has it), however the awful stuff produced by Cadbury / equivalent shouldn't be allowed to be called chocolate. We weaned ourselves off the easy-grab chocolate bar onto darker chocolate, reducing the sugar and satisfying the taste with a smaller number of squares from a bar of Lindt. Supermarket own-brand (specifically the finest / best / etc) have improved significantly, and the key is to segue to richer flavour through a middle ground. Trying 70% dark after years of eating 20% yorkie bars isn't going to work. Instead look for 40-50% cocoa, sometimes labelled 'supermilk' - it has the smoothness and enjoyable eating of a milk chocolate whilst having a better cocoa flavour and less sugar, allowing a transition towards the higher quality. You'll also be less likely to eat the whole bar as after a certain point you'll be sated and simply wont want any more.
We've done the same with alcohol, vastly reducing the quantity by opting for a nicer bottle of something that we enjoy together. We're not trying to become hipster sommeliers / annoying party guests, it's more that we have come to require less than we used to whilst still being satisfied. It took a little time but has worked to improve our relationship with food and drink, and to enjoy things much more than we used to.