I have a friend who used to drink nothing but Diet Coke. He went through a few 2l bottles a day. According to that link (assuming it's the same in Europe), Diet Coke is 125mg per 8 ounces, so a 2l bottle is 125 / 8 x 70.4 = 1100mg. So if he drank four 2l bottles, that's over the daily limit.