It's probably one of the most commonly accepted medical myths. Parents, teachers, babysitters, will tell you that the reason young Tommy or Sally is bouncing off the walls is because they are suffering from a "sugar high". Where does this idea come from?
It may date back to the 70's.
Back in 1973, the Feingold Diet became all the range. Allergist Dr Benjamin Feingold proposed removing food additives (dyes and artificial flavours) from childrens' diets to reduce the risk of hyperactivity. Sugar somehow got added to the mix. All sorts of studies done since that time have effectively refuted this link. Food additives and sugar do not cause hyperactivity although they may have other effects on a child's health.
So why does this myth persist?
Think about when kids are most likely to get lots of sugary foods: birthday parties, Halloween, etc. These are situations where kids will tend to be "hyper" even without sugar on board!
On the other hand, I don't want you to think that I am giving anyone permission to give our kids as much sugar as they want. Far from it. Sugar provides empty calories without any additional nutritional benefit. If food needs to be sweetened (and I would argue that it's best to train our children's' palates to enjoy foods that aren't very sweet), we can use honey or other sweeteners. Sugar is linked to obesity, diabetes and cavities and should not be a part of our children's diets.
So please do limit their sugar intake but do it for a scientifically valid reason rather than because of a myth. And as for Halloween, let's try to encourage healthier alternatives. As for those sugar laden treats they may receive, spacing out their consumption and limiting the amount that they consume at any time is a wise move in any case.