If you want to get pedantically technical, we can say that you need to either consume the carbohydrates that will break down specifically into glucose or foods that directly contain glucose itself, but you can't survive with literally 0 glucose.

While we don't need to consume added sugars or already simple glucose, fructose, maltose, or sucrose, we must consume enough carbohydrates that will break down into glucose to support brain function.

Your words specifically were

>There is no dietary need for sugar.

Which is simply untrue, unless your making the argument that we could mainline glucose infused saline or something to avoid eating it, but that's silly.