Here's something you shouldn't do. Tried and tested by me not on purpose, though.
This morning when I woke up I was so thirsty and felt like having something cold so I went to the fridge and the only thing I had in there was Redbull and thought why the heck not, it will wake me up, too. So I figured I would shoot two birds with one stone and drank almost half of it without stopping. I don't like Redbull and I don't drink it usually and I don't drink coffee either, but that's not the point. After a few hours, dunno if it was the fact that I drank it without eating anything before or after, or just the Redbull itself, but it felt like I had a drilling machine inside my stomach, lol. Also don't eat pizza for two weeks, but that's a whole other story... Somebody stop me, hah... *le sigh*