We limit dd 6 yo to 2 treats a day. 1 treat is about 100 calories. This is more than i'd really like her to have, but she seems to be unable to deal with having less & becomes deceptive and tryies to cheat the system too much. We put it in her hands as much as we can - when she asks if she can have a treat, we ask her how many treats have you had? so can you have a treat or not? The reality is that I don't always have control of what she's eating, so i need her to be on the same page and working with the program. I want to get her thinking about what she's eating and managing it as much as she can. I'm mostly interested in teaching her to deal with cravings, so I feel that putting my foot down and enforcing something she can't abide by doesn't further that goal. I try and compensate a bit by not having too much really bad stuff in the house - most treats have some kind of nurtitional value, and unredeemable stuff like chips, pop, and candy don't make frequent appearances in the house. We also have occasional free days, mostly at parties or on vacation where I know the temptation is going to be overwhelming. The whole plan is basically to avoid hoarding and binging and lying, while increasing healthy food as much as possible.
We have also made some other rules to support healthier eating - no treats before you've had 2 healthy things to eat, no eating treats in front of the TV, drink a glass of water before eating, etc. We have a number of healthier snacks that dd enjoys that are not on the treats list, such as sweetened yogurt, chocolate milk and fruit juice popsicles, that she can have for a sugar hit if she needs to. We put out some healthy things on the table always, like a bowl of cheerios and some carrots, which often get grabbed and seem to make healthier choices more likely. It seems that the longer she goes without eating the more likely she is to choose high sugar items. If she gets something as soon as she thinks "im hungry' it seems to be more manageable. We do what we can to increase her protein and fibre intake as much as possible, use whole grains as much as possible etc. We talk a lot about why we make the food choices we do, the good things that various foods do for you, the importance of caring for your body and the dangers of too much sugar and junk food.
This isn't ideal, I'll be the first to admit. I'm not a real foodie kind of mom, but i would prefer that my youngest had a healthier diet. Ultimately, she is a healthy, active and if anything slightly underweight kid, tho, so I've decided I've just got to work with what we've got and do our best to encourage her to eat better, respect her body and set her up for success as much as we can.