I've given up nicotine, alcohol, caffeine and sugar all at once before now. It was too much!! What I did notice was that it certainly focused the mind away from cigarettes and alcohol, and even coffee/caffeine. I became obsessed with sugar! and the cravings for sugar were ridiculous!
This time round I've decided that nicotine and alcohol need to be primary focus and not to worry about anything else. I have had to cut down my caffeine intake though as nicotine doubles the rate by which the body depletes caffeine. I'd be flying now if I hadn't cut down!
Personally, I have never taken energy drinks and I wouldn't let my kids anywhere near them, they are so bad for you... but not as bad as the drink!! What I would say is that if you start to feel that you are replacing an addiction to alcohol with an addiction to energy drinks, you should knock them on the head.
Good luck
R.