When I was young but starting to control my own food choices, I used to have a great time teasing my mother by choosing foods with artificial colours (flavours etc.)She was one for believing all artificial substances in foods should be considered "bad" and to be avoided, even if all available research pointed to them being 100% safe. I would be into jelly, cordial, soft-drink, lollies and all those things that I was deprived of as a young child. This extended into my own children, where it would give me pleasure to feed them froot loops just to annoy my mother. That was until Zac came along. We were quite sure some foods were making him hyper-active. The before and after drinking creaming soda at Sizzler was quite stark. He liked banana lollies, so we moved towards using them as "bribes" like we did for the other children to help control behaviour. Lo and behold, his behaviour got distinctively worse when we tried that tactic. Then one day we had fed all the kids froot loops, and Zac too since he would have been jealous if he had missed out. Not long after he started being particularly loud and got cranky at the slightest provocation. We were having a party later that day (he was about 2 and a half years old then) but he refused to get dressed, insisting he stay naked. He wasn't much into clothes and we had a lot to do, so we moved on after a half an hour of screaming. When relatives arrived for the party they mostly felt his nakedness to be unacceptable, which led to another round of screaming for 30 minutes at a time as various relatives thought they knew Zac behaviour and felt they could convince him otherwise. The behaviour, if anything, intensified and the screaming started happening with any interaction. The party was a complete disaster, but Zac hadn't quite finished with us. The screaming and hyperactivity kept going and going through the evening. It stopped only when Zac crashed to the ground in complete exhaustion and fell asleep suddenly. As can be expected, the froot loops hit the bin. We converted to the all natural confectionary company, which has been a bit of a godsend. We made a mental note of every single food-stuff which triggered hyperactivity, to determine the additives and commercial foodstuffs to avoid. Things like artificial banana flavour, bright blue and red food colouring, some preservatives. Confectionary is a minefield of probable triggers. At home we stock only the all-natural lollies and that is working quite well. There are a raft of complications outside of home, with friends, teachers, parents etc. casually unaware of the risks.
It is easy to generalise, and put the blame of other's hyperactivity on artificial additives, but it is a lot more complicated than that. That said, additives are a significant contributing factor to a scary proportion of diagnosed hyperactive and autistic cases. It is impossibly hard to narrow down triggers when they are different for every individual, and behaviour profiles are often a lot more subtle and there are time delays, and for some behaviours, diet can have a residual effect that lasts weeks, and is not necessarily isolated to artificial substances. One rule of thumb is that it isn't the sugar that gives a sugar high, but the artificial stuff that goes with it. Zac can have sugar all day and still be in control.
Suffice it to say that this issue has gone full circle for me, and now I obsessively check every food we buy for additives. We avoid them for the whole family. If they have this much effect on Zac, surely they can't be that good for the rest of us either!