Maybe you could try to explain the different kinds of sugars and how some are better than others. I guess this would depend on your childs age. But for example, fruit and juice have tons of sugar, but they are fruit sugars, which are not bad for you (in my opinion, and obviously in moderation with juice). You would never tell your child not to eat an apple and they probably haven't realized it is packed with sugar. Then there are varying levels of refined sugars. If I sweeten things at home, I try to use honey as a first choice. Then white sugar. Last choice would be high fructose corn syrup. You aren't cooking with HFCS, and maybe just stress that you try to avoid that. People just say 'sugar' when they talk about soda and candy and store bought cookies, but in actuality it is HFCS in most cases. I also do not have a problem with moderation, but try to stick to the best sugar possible for the situation. Our parents grew up eating dessert on a regular basis, but usually that was homemade with regular sugar. These days that is not what it is in store bought food, and I personally think that is most of the problem with weight and health issues now.
Anyway, that is how I would approach it if your child is old enough to understand the differences. All things in moderation, and that there are degrees of 'bad' when talking about sugar, fats, etc.
