Your body needs sugar to function. Your body can convert food into a usable form of sugar for energy but the problem is refined sugar is added to many different foods and you can see this by checking the labels..the most common is high fructose corn syrup. Problems like Diabetes are rampant these days because people are throwing their bodies out of whack with that stuff. The body cannot handle that overload and excess sugar.
Sugars in fruit and honey, etc are minor and not enough to throw your body out of whack. The sugars that occur naturally such as in fruit and honey are loaded with other minerals, enzymes and nutrients that give them a healthy benefit and balance. White sugar is just stripped, refined and empty.
It's best to stick with foods that have natural sugars in it. Even with natural sugars like honey and molasses, it is still best not to overdue. I read many times that refined sugar can lower the immune system for some hours but I am not exactly sure on the science behind it.
There are many problems that manifest if one goes overboard on processed sugars. From my own experience, i notice some problems arise when I overdue on sugar. It definitely isn't good if you constantly consume it over a period of time. If you find yourself craving sugar all the time, then you know that you have some sort of imbalance.
Of course sometimes I eat food with refined sugar but after a while of getting off the stuff, you will see that it tastes way too sweet and artificial. I went off many forms of sugar for a while and I definitely felt better.