Personally I never (except when a pub accidentally gave me one) drink sugary Coke, I will only drink Coke Zero or my preference Pepsi Max. I know these don’t spike my blood sugar, but the only way to check they are Ok for you is to test blood sugar before and two hours after.
This is what sugary Coke did to me!
I avoid all sugary drinks these days, and that normally includes milk apart from a splash in tea. I don't have any problem with artificial sweeteners and regularly drink Coke Zero and a couple of supermarket own brand caffeine drinks.