The Myth of the Sugar High

October 16, 2019 | By

by Dan Seigel, LMFT

Halloween is upon us, and children everywhere are gearing up for evenings filled with costumes, trick-or-treating, and the promise of candy coming out of their noses. Parents, on the other hand, are ready for sweaty little goblins (at least down South, where fall may or may not wind its way to the end of October) and the promise of hyperactive children on—gasp—the dreaded SUGAR HIGH!

Let’s talk about that sugar high, though. For decades, we’ve been warned about the dangers of sugar-filled candy, sweets and sodas that have plagued our children’s behavior. Parents are well aware of the hyperactive, amped up 7-year-olds whizzing from wall to wall without any promise of going to bed. And don’t get them started on the ADHD kids!

But there’s something amiss this Halloween, and it has much to do with the myth that sugar makes children hyper. You read that right: MYTH. Where does this myth come from? The easiest answer is the “expectancy bias,” with a not-so-subtle helping from the “anecdotal fallacy.” 

Expectancy bias (more rightly the called observer-expectancy effect) is a fallacy in research in which the expectations of the researchers affect the outcomes of the test. To put in in Halloween terms, parents who expect a sugar high will get a sugar high. One study gave children soft drinks—some laced with sugar, others with artificial sweeteners—and parents were told which was which. Parents of children with sugary drinks rated their children as significantly more hyperactive than the other parents. The catch? None of the drinks contained sugar. This study has been repeated in various ways, from various angles, over the past 20 years.

“But my child…” Yes, I know, and it’s very possible that your child does get hyped up with sugar intake. Think about it, though: when do they get highly processed sugars? Birthday parties, weekends, fun events like carnivals, and Halloween? What kid isn’t already amped up? We have a tendency to fall for the anecdotal fallacy as well, where we take the outliers to the data (our child, my niece, their son) and apply it as fact because we have direct experience with something that doesn’t fit the data. Just because your child gets hyperactive doesn’t mean that a) it’s the sugar, or b) it’s true for everyone. That’s the anecdotal effect, and science doesn’t support it.

What about kids with ADHD, though? Surely they have more problems with sugar, since they already struggle with hyperactivity and impulse control? Sugar causes hyperactivity in my ADHD kid!! Well, the converse may be more accurate; kids with ADHD are more likely to consume large amounts of sugar. ADHD is primarily an issue with the balance between dopamine (pleasure, motivation) and the actions of the prefrontal cortex (inhibiting behaviors, waiting for dessert). Over time, consumption of high sugar drinks and foods leads to reduced “signaling” of dopamine in the brain, setting up a situation where children seek out that pleasurable sweetness in an almost addicted way. Furthermore, kids with ADHD are less likely to be able to control their impulse to grab that Halloween candy by the fistful, and are more likely to exhibit their already hyper behaviors in response to getting that sugary sweet taste.

This all may come as a surprise to you, but it’s out there in Research Land. Unfortunately most research isn’t written for the average reader, but rather for academics, and it’s left to journalists to interpret the results. When you’re unsure, talk to your doctor or mental health professional about it. They probably know what the research says, and if not, they will know soon after you ask.

Sugar is a choice, not an inherent danger. High sugar diets are the direct cause of cavities, obesity, and Type 2 diabetes, so monitor your child’s sugar intake, not because of hyperactivity but because it’s your choice as their parent as to how much sugar they should have.

So go out there and trick-or-treat, and watch out for those razor blades in the cand…oh right, anecdotal effect. Sorry.


Some further reading out in Research Land:

ADHD Knowledge, Misconceptions and Treatment

ADHD: Is it time to reappraise the role of sugar

Does sucrose or aspartame cause hyperactivity in children?

Hyperactivity: is candy causal? (abstract only)

Filed in: ADHD, Children & Youth, Family, Library

Comments are closed.