If you’ve ever joked that your snack habit is just “fuel for your brain,” you’re not entirely wrong.

The human brain—though only about 2% of your body weight—uses roughly 20% of your daily energy, most of it in the form of glucose, a simple sugar. It’s the primary fuel for your neurons, which need a constant supply to transmit signals, form thoughts, store memories, and keep your entire nervous system in sync.

So yes, your brain loves sugar. But not in the way that soda and candy would suggest.

You see, the body doesn’t need added sugar to fuel the brain. It’s beautifully designed to break down complex carbohydrates—like whole grains, fruits, and vegetables—into just the right amount of glucose. That’s a slow, steady release of energy. Refined sugar, on the other hand, is like handing your brain a firehose when it asked for a faucet.

Too much, too fast.

That initial spike may feel like a mental “boost,” but it’s quickly followed by a crash. Over time, those surges can dull the brain’s sensitivity to insulin, a hormone that helps regulate sugar levels. And researchers now link chronic high sugar intake with brain fog, mood swings, and even memory issues.

Still, it’s fascinating, isn’t it? The brain doesn’t store energy. It relies entirely on what we provide—and how consistently we provide it.

So, if we’re serious about feeding our brain, maybe the best thing isn’t what’s sweet—but what’s wise.

After all, “The wise one is cautious and turns away from evil, but the stupid one is reckless and overconfident” (Proverbs 14:16). That principle applies just as much to our diet as to our decisions. Overindulgence might feel smart in the moment—but wisdom thinks ahead.

So the next time someone teases you for eating a banana instead of a candy bar, you can smile and say, “I’m feeding my brain. Just not frying it.”