“Sugar rush” in children seems to be confirmation bias

Go to a child’s birthday party, and the kids will have a lot of juice and cupcakes and run around while the adults say things like “They’re on a sugar high now!” 

But a meta-analysis of 23 studies on sugar found no effect on children’s behavior or cognition.

So why do so many people think that sugar makes children wired? Lots of the occasions when kids get extra sweets (parties, holidays) also involve extra excitement. There are other times when kids have high energy without sugar, but people don’t comment on it. This kind of selectiveness in paying attention to evidence is selection bias.

In a study about adult expectations of parents who believed their sons were behaviorally sensitive to sugar: “In the experimental group, mothers were told their children had received a large dose of sugar, whereas in the control condition mothers were told their sons received a placebo; all children actually received the placebo (aspartame). Mothers and sons were videotaped while interacting together and each mother was then questioned about the interaction. Mothers in the sugar expectancy condition rated their children as significantly more hyperactive.”

I can’t find any studies on this, but I wouldn’t be surprised if adults saying things like “they’re going to be bouncing off the walls after all this candy” increases hyperactivity in children who hear this cue and live up to expectations. I wish people would stop saying things like this.