My two eat a lot of junk - balanced off with good stuff too - but the one thing that sends them completely hyper, bouncing off the walls hyper is Vimto! I just won't let them have it at all. Then the other week we were over at my Mother in law's and she said she'd got Vimto instead of Ribena - as they were staying over for the night and we were going out I just let her get on with it.
