After reading the "discussion" on the topic of sugar, it seems that the reason for the disagreement is that there are different ideas of "health" and "healthful eating."
Here are the two general ideas I'm getting:
1) Conservative (Traditional) "Healthy Balanced Diet"
which generally entails eating from the four food groups, getting a minimum of different vitamins and minerals, eating moderate/small amounts of sugar, fats (the top triangle on the pyramid) but not large amounts.
2) Dynamic Super Health
a lot of different ideas here, but most involve eating ONLY healthy foods, and perhaps supplements, and avoiding most or all unhealthy things (and there are a lot of them!)
Obviously, people from these two camps will disagree with each other. A lot. They will disagree about which foods are healthy, or not... how much (if at all) one can have of them... how one is too extreme, how the other is not enough for good health, etc.
I just feel that this is the reason for the disagreement, and until one of you changes sides, you'll probably never agree.
(Personally, I fall somewhere between the two, but more towards #2. I feel that Sugar is detrimental to health, and should not be a part of the DAILY diet. But, if on occasion I eat a piece of cake or such, I won't kick myself too much. I don't think of it having a place in a healthy Diet - I just consider it a cheat. As long as you don't cheat too much, you won't get caught :-) !)