Does Sugar Makes Kids Hyper? Here's What the Research Says about the Sugar High.

At every children's birthday party, Halloween excursion, or Bring Your Cool High Carb Aunt to School Day (a girl can dream), a familiar refrain echoes in the minds of parents: Watch out for the sugar high. The kids are going to be bouncing off the walls. Hide the good china.

There's just one problem. The sugar high isn't real.

Decades of research have failed to find any link between sugar consumption and hyperactivity in children. None. Not in studies of kids with ADHD, not in studies of kids without ADHD, not in studies that loaded children up with so much sucrose their teeth should have filed a restraining order. The sugar high myth is one of the most persistent in modern parenting, and it has roughly the same scientific footing as crystal healing, but without the fun trips to rock shops in Sedona.

For athletes, this matters even more than it does for parents. The same cultural panic that turned birthday cake into a behavioral hazard has convinced active people that simple sugars during exercise will somehow betray them. They won't.

Where did the sugar high myth come from?

The story starts in 1973, with a pediatric allergist named Benjamin Feingold. Feingold proposed that artificial colors, flavors, and salicylates caused hyperactivity in children, and that an elimination diet could cure behavioral disorders. His ideas spread fast. Parent groups formed. Cookbooks followed. Sugar was eventually swept up into the panic, even though Feingold's original hypothesis didn't focus on it, and the specter of these theories still haunts parenting Facebook groups today.

By the 1980s, "sugar makes kids crazy" had calcified into folk wisdom. It fit neatly into a broader cultural anxiety about processed foods and modern parenting. It also conveniently explained any tantrum that happened within four hours of a cupcake. Confirmation bias is everywhere, once you start looking for it.

The problem is that nobody had actually tested it.

Does sugar cause hyperactivity in kids?

No.

In 1995, researchers at Vanderbilt published a meta-analysis in JAMA examining sixteen double-blind, placebo-controlled studies on sugar and children's behavior (Wolraich et al., 1995). The conclusion was unambiguous. Sugar does not affect behavior or cognitive performance in children, including children diagnosed with ADHD.

Sixteen studies. None of them found an effect. The authors noted that the cultural belief in sugar-induced hyperactivity was so entrenched that even strong evidence to the contrary seemed unlikely to change minds.

That theory, unfortunately, did turn out to be correct.

The most damning study came from Hoover and Milich (1994), who told a group of mothers that their children had been given a large dose of sugar. The children had actually received a placebo. The mothers, watching the same children doing the same things, rated their behavior as significantly more hyperactive than mothers in the control condition. They reported more interruptions, more physical activity, more general unruliness. The kids hadn't changed. The expectation had.

This is what scientists call the expectancy effect. It's also what the rest of us call seeing what we want to see.

Is the sugar crash real?

The cousin of the sugar high is the sugar crash: the alleged post-candy slump where you go from euphoric to comatose in twenty minutes.

At this point, dunking on the somehow-still-not-defunct Spring Energy gel feels about as brave as trashing Nickelback, but that chart has haunted my dreams (and my nutrition discussions) for years.

The language of "spike" and "crash" gets weaponized to sell products that solve a mostly fake fear. The story goes like this: eat a gummy bear, an energy gel, a banana, and your blood glucose soars to Icarus levels before crashing and burning, Hindenburg-style, leaving you cratered and more drained than if you'd had no sugar at all.

This one has slightly more biological plausibility than the high. The cultural version still mostly isn't real.

What can happen, in some people, is a small dip in blood glucose after a rapid spike. It tends to show up when sugar is eaten alone, without fat or protein, by someone who is sedentary. This is called reactive hypoglycemia, and it is both rare and mild. For most people, the "crash" they describe is some mix of expectation, dehydration, the normal energy swings of an ordinary day, and the fact that they ate a doughnut for breakfast and are simply hungry by 11 a.m.

For active people, the picture is even simpler. Sugar consumed during exercise does not crash you. It fuels you. The entire architecture of endurance nutrition, from gels to chews to sports drinks, is built on the fact that simple carbohydrates absorb quickly and go straight to your working muscles. That is a feature, not a bug. Which is why the crash, during activity, has the least mysterious solution in all of sports science: keep fueling.

If you have ever bonked at mile twenty and resurrected yourself with a Coke at the aid station, you have personally falsified the sugar crash myth.

Why the sugar high myth refuses to die

Persistent myths usually persist because they're doing cultural work. The sugar high myth does a lot of cultural work.

It gives parents a tidy explanation for normal child behavior, which is, on average, weird and energetic. It gives the wellness industry a villain, which is profitable. It gives diet culture a moral framework that maps food onto behavior and behavior onto character. It tells women, in particular, that their job is to police what enters the household, lest chaos descend.

Sugar, in this framing, isn't just a carbohydrate. It's a threat. It's a moral test. It's something to be feared, monitored, and earned back through restriction.

This is nonsense, and it's expensive nonsense. The global sugar substitute market is worth billions. The "low sugar" branding industry is worth more. A great deal of money depends on you continuing to believe that sucrose is doing something dramatic to your brain.

It isn't.

Is sugar bad for athletes?

If you train, sugar is one of the most useful tools in your kitchen. Glucose and fructose move into circulation quickly. Mixed together, they use different transporters, which means you can absorb more carbohydrate per hour than you could from glucose alone. This is why most modern endurance fuels combine the two. It's also why a banana and a handful of gummy worms is, biochemically, a respectable mid-long-run snack.

The fear of sugar is not protecting your performance. In many cases, it's degrading it. Underfueled athletes, particularly menstruating athletes, are more vulnerable to fatigue, injury, hormonal disruption, and low energy availability. The cultural messaging that frames sugar as a moral problem makes it harder for people to fuel adequately, especially in sports where thinness is rewarded.

We've covered this on the main feed more than once. The full archive lives on the podcast page, and we'll be unpacking more of the carbohydrate science in upcoming episodes.

The bottom line on the sugar high

The sugar high is not real. The science has been clear since 1995, and the cultural belief has outlasted the evidence by three decades because it's serving purposes that have nothing to do with biology. Sugar is a carbohydrate. Your body has elegant, well-rehearsed systems for using it. Children do not become feral from cake. Athletes do not collapse from gels. The villain in this story isn't sucrose. It's the industry that's been selling you the fear of it.

This is exactly the kind of conversation that keeps going in the Patreon community, where Kylee answers fueling questions in the weekly nutrition thread and the discussion threads are where the weirder sugar myths get aired out. If you want in on that, the front door is here.

References

Feingold, B. F. (1975). Hyperkinesis and learning disabilities linked to artificial food flavors and colors. American Journal of Nursing, 75(5), 797–803.

Hoover, D. W., & Milich, R. (1994). Effects of sugar ingestion expectancies on mother-child interactions. Journal of Abnormal Child Psychology, 22(4), 501–515.

Wolraich, M. L., Wilson, D. B., & White, J. W. (1995). The effect of sugar on behavior or cognition in children: A meta-analysis. JAMA, 274(20), 1617–1621.