When my son was home from foster care he started doing this. When I discussed it with our family therapist she told me that when children do this punishing them for it and trying to enforce them not eating the sweet stuff only results in them doing it more and can cause eating disorders because the child starts hiding it and binging on it and then trying to throw it up because they did something bad.

She said the best approach when this happens is allow the child to help plan the meals for the week. Basically sit down and write the food groups down and have them pick something from each food group per meal that they are allowed to plan. Include in that plan sweets, that way the child sees there is going to be the favorite items but nutrician comes first. Hang the childs "menu" for the meal(s) he planned for the week.

Then have the child go shopping and help pick up the things, this way the child knows shopping means going by the shopping list that way he knows what is being bought and for what so he doesn't feel he has to hide and binge to get fed. Then at home have the child help put groceries away. In the process mention here's the (sweet) for this or for that.

The only consequence for getting into the sweets was a natural consequence of not having that sweet - not as in forbidded but as in we only bought what was planned and if it got ate before that planned meal then sorry its gone. you ate it on this day so now you have to wait until this day when we sit down and you plan what you want next week.

The first time we did this my son had a great time planning buying and eating ahead of his plan. But the day came and he went to help cook his planned menu and realized uh oh no sweets because he already at it. and there was no more until the day when he got to plan the next weeks meals with me.( Our day to plan menu(s) was saturday mornings).

That natural consequence got him. He did not like it. He had only himself to answer to for his misbehavior because he chose what day to have that sweet and did not follow through with waiting so he was out of luck when the day came.

The second time he planned a menu and sweet he would go to eat it then look at his posted menu and put it back on his own and X'ed of days on the callendar counting down when he could allow himself to eat it.

That plan stopped his gorging on sweets and he was learning how to choose nutricious meals and what it cost to buy that food. AND I did not have to be the one to come up with consequences for his misbehavior. he got what was naturally coming to him, with out a battle.