What is the difference between sugar grams and sugar alcohol grams?

I wonder because sugar sometimeas makes me naseated , and i want to get some protien bars and they always have that sugar achohol stuff , so is this like fake sugar and what is its purpose ? thanks

sugar alcohols are not fake sugar. It is a hydrogenated sugar. So they add an OH group, hence alcohol. Sugar alcohols are not readily absorbed in the intestine due to this change. They are used as substitutes for sugar in addition to artificial sweeteners but they are not artificial. So some sweetness and calories come from them but greatly reduced compared to regular sugar. They also cannot be broken down by the bacteria in your mouth-look on sugar-free gum and you'll see sugar alcohol or erythritol, sorbitol, etc on the label. This means less chance for cavities.

sugar grams are, well, sugar, while sugar alcohol is synthetic sweetener (basically chemicals) without any calories. Some people think they cause cancer, but there's no reliable scientific evidence to support that theory.