Sugar causes blood sugar and insulin levels to spike. If you have belly fat, you are becoming insulin resistant, the first step to diabetes. Your pancreas is working too hard, leading to other health issues.
Sugar is in practically everything and has at least 50 different names. Don’t be fooled by claims of “healthy” sugars. Sugar is sugar. Avoid it in drinks, cookies, spaghetti sauce, ketchup, etc. Don’t bother with artificial sugars – they are as bad if not worse than regular sugar.