Just in time for Halloween, the Los Angeles Times turns the conventional wisdom on sugar highs inside out and upside down. (Which is the sort of thing that gets the conventional wisdom all worked up before bedtime, of course.) According to the story (registration required), and almost all the scientists quoted in it, the sugar high is a myth. To phrase that claim more rigorously, here’s Dian Dooley, a professor of human nutrition, food, and animal sciences: “There is no scientific basis to the idea that sugar and/or candy has any major effect on children’s behavior, particularly if they eat OK.”

It’s odd because, like many things that turn out to be wrong, sugar highs make intuitive sense: After all, the body gets energy from glucose, which comes from sugar. But a well-functioning body keeps glucose levels steady through insulin production, although that process isn’t always instantaneous. However, if glucose levels are elevated for an extended period, evidence thus far shows that “instead of energizing a person as you’d expect, it actually makes a person sleepy.”

What looks like a sugar high on Halloween might be caused by small amounts of caffeine in candy, especially if those candies are being downed in bag-size quantities. Or it might be caused by—get this—”genuine excitement.” There is evidence that parents may create sugar highs: “If parents expect a child to be hyper after eating something full of sugar, then that’s what they’ll see.” Studies have backed this up. And as a doctor at Stanford says, “I would never try to convince parents otherwise. You can’t tell them it doesn’t happen because, for them, it does happen.”

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