Not sure about McD's, but in most of the US, Coke uses high fructose corn syrup rather than sugar. There have been threads about that here, but the summary is that a lot of people seek out the sugar version. For example, some Costco stores import Mexican coke and sell it at a premium. Coke marked Kosher for Passover also uses sugar. Just do an advanced search here on "Coke sugar", all dates.