I've read a few threads from people who are determined that their dc's will eat only good, wholesome food, with all junk to be outlawed. All very understandable and honourable.
But I just want to share the story of my cousins. There are four of them and when they were growing up their mum (my aunt) completely banned anything sugary/unhealthy. Even when they were out with other children, it was forbidden.
As soon as the kids were old enough, they would buy sweets and stash them away so that their mum didn't know.
They are now in their twenties. Two of them are morbidly obese and have a problem with compulsive eating, one is bulimic (for the same reason) and only the fourth is "normal" but admits he really struggles when he does eat sweet things and finds he gorges on them.
Of course I'm not sayiing this will definitely happen to those denied sweets as children but just that you need to teach moderation as part of a healthy diet because my cousins clearly have no concept of that.