So there's a study stating drinking diet-soda mixers gets you drunk fatser rather than consuming higher calories. It's been shown that diet mixers increased breath-alcohol content (BAC) by 18%... that's just about the same as having a standard drink. According to Time, "Previous work found that the stomach reacts to sugary drinks as though they are food, working to digest the calories. Eating solid food while drinking significantly reduces BAC, by 20% to 57%, and sugary drinks seem to act similarly, keeping alcohol in the stomach longer, slowing down its release into the bloodstream."

Unfortunately, the stomach doesnt realize what you consume isn't food so you its just as effective as drinking on an empty stomach...