I remember hearing about baby coffee from an italian family. The little kids would feel grown up for being allowed to have coffee. What it really was mostly was sweetened milk with a small splash of coffee
Does caffine stunt growth btw, or is that one of those food myths?
I think not giving your kids caffine pop is a good idea. Why get them addcted to something this early on. Yes there is caffine in many things, but I have seen full blown coke addicts that are extreamly young. They also don't need the stimulent. They are wired for sound as is.
If your kids really enjoy sodas, maybe get diet Rite or another caffine free, sugar free soda. Or make your own italian sodas using seltzer water and flavored syrups.
If someone is giving them mountain dew, it's not just the caffine but a sugar punch as well. The monster part could come from being over excited at getting a treat too. I can get my son bouncing off the walls with no sugar or caffine needed at times
If you are worried about caffine you might also want to look at hot chocolate, it's loaded. Instead use something like ovalteen, homade chocoalte and so on.