Previous: Turning Your Leftovers Into Fuel
Next: All About Allergies



View count:460,507
Last sync:2023-01-19 23:15
Your brain uses tons of calories, just in its daily work of keeping you alive. So does thinking extra hard use even MORE calories? QQ fills you in!

Hosted by: Hank Green
Messages from our Subbable subscribers:

“Michael, always be curious, Love Mom and Dad.” - Jennifer Daniels

“Carl Sandburg Junior High STEM students say: Science ROCKS!” - Al Stevenson

“na na na na na na na na na Batman!” - Jude Limus

"Happy 3 years together Katie :-) Here's for many more" - Lionel Pierson

“Greg recommends Alert the Medic - The Phantom Moves” - Greg

“Thanks for keeping the world a more educated place SciShow!!” - Collin

“Thanks for not forgetting to be awesome, Michelle & Shannon!” - April Ashby

“Happy 1st Birthday, Austin!” - April Ashby

“My kids love SciShow, keep it gong!” - John Stelling

“Science rocks!” - Jordan Hawkins
Dooblydoo thanks go to the following Patreon supporters -- we couldn't make SciShow without them! Shout out to Justin Lentz, John Szymakowski, Ruben Galvao, and Peso255.
Like SciShow? Want to help support us, and also get things to put on your walls, cover your torso and hold your liquids? Check out our awesome products over at DFTBA Records:

Or help support us by becoming our patron on Patreon:
Looking for SciShow elsewhere on the internet?

What if you could lose weight just by sitting around thinking -- finding the square roots of stuff in your head, considering the use of negative space in the art of Matisse, or coming up with a Grand Unified Theory of particle physics?   That would be not so bad.   I mean, if I had to choose, I would rather think hard than work hard.   And the fact is, you actually do burn calories by thinking.   Just ... not a lot.    I mean you’re not going to be able to think away that bag of Doritos. It’s just not going to happen.   As we’ve mentioned before, your brain is voracious in its hunger for energy: At least 10 to 20 percent of the calories that your body uses when it’s at rest is taken up by your brain.   You might be, like, picturing the inside of your brain and think “Yeah, all my neurons are using all that electricity to communicate”. But it’s not like your brain’s circuits are buzzing with streams of electrons like your computer or phone is.   Instead, your neurons communicate with each other in a number of different ways. One is using chemical signals called neurotransmitters, and much of the energy that thinking demands actually goes into producing and releasing those chemicals.   So, how much energy are we talking about?   Well, at rest, the best estimates are that your entire brain uses about a fifth of a calorie per minute.   But can you burn more calories by thinking ... harder?   Well, scientists have actually tried to measure that.   A couple of experiments conducted in Britain, for example, found that levels of blood glucose dropped when people were asked to perform intellectually challenging tasks, like solving puzzles, compared to those who did simple, you might say, mindless tasks, like pressing a button repeatedly.   Plus, brain scans of subjects who were asked to do some serious thinking -- like doing multiplication problems in their head -- showed an increase in glucose uptake directly to the brain.   But it wasn’t, like, a ton of difference.   Research suggests that, when you’re consciously chugging away as hard as you can, your brain might consume, like, 1.5 calories per minute -- so, an extra calorie, maybe a calorie and a quarter, more than you would at rest.   Considering that your brain really only deliberates seriously about things for a couple minutes at a time, most estimates are that you burn anywhere from 10 to 50 calories a day from the act of thinking.   So thinking, yes, it burns calories… but probably not enough to be super significant. But really? Is that why you’re thinking anyway? No, I don’t think so.   Big thanks to our Patron Ray for asking us this question, and especially to all of our supporters on Patreon, where, if you support us at at least four dollars per month, you can submit your questions to be answered right here on SciShow Quick Questions. And if you want to keep getting smarter with us, you can go to, and subscribe.