If the brain uses the most calories of any organ, is it possible to burn fat by thinking very hard? Brian Eyack, Aylesbury
Send new questions to nq@theguardian.com.
Readers reply
Yes, think about your bank balance; that should worry off plenty of pounds.
Bryn
Maybe if you think you have eaten when actually you haven’t. What would be helpful to know is whether the brain’s calorie use varies significantly by the level of mental activity or is fairly constant. And also is it true that the brain is the most energy-hungry organ? Other candidates include the liver/spleen considered as one system. seedysolipsist
Well, being anxious and worrying could get your body ready for action and use up calories. You probably could lose weight by excessive worrying, but probably also end up taking alcohol to calm yourself down. So you would have a skinny brain and a fat body. DESI121
The brain is the organ that most needs a constant temperature, so a good proportion of those calories are used to keep it warm. If “thinking very hard” did use more calories than not thinking, the net result would be heat – and those calories would largely be substituting for those which would be used maintaining the temperature. So no, “thinking very hard” isn’t going to use much in the way of additional calories, even if some were used in a slightly different way. leadballoon
Ah, you’re making a crucial error there. You need to think fast. ddtqm
Thank you for the question; it’s a real weight off my mind. Gordon Lawrie
I have been thinking about this topic for a long time, since reading an ESPN article about the staggering energy needs of world-leading chess players at days-long competitions. To the naive observer, the competition entrants are sedentary for most or all of every day, yet research suggests they are using several thousand more calories each day than they would if they were, say, loafing on the sofa watching Gilmore Girls. There are reports of players losing five or more kilos of bodyweight in just a few days during chess competitions. Apparently, Fabiano Caruana can drop from 135lbs to under 120 during a 10-day tournament. emmahatred
No. Source: I did a maths degree and got fatter and fatter despite all the thinking I did … Luckyjenjen
Sort of. I had depression and did endless amounts of rumination. Lost a ton of weight very quickly. Malalai
That’s a question I asked myself once and did some research on. The answer is this: no. The couple of calories extra that do get burned are not going to make any difference. nina1414
I know someone who thinks very deeply, and does post-grad level of maths. When he’s thinking he burns off huge amounts of energy and the top of his head gets hot! He’s pretty thin tbh. GreenAndNowGrey
Let’s see now, thinking about lumps of lead, and heavy metal songs. Quick! Bathroom scales. Right, noted, now concentrating on being lighthearted, hydrogen atoms and soufflés. Rushes back to bathroom, no difference not an ounce. Then it occurs to me, you can’t burn fat without a wick, feeling all over top of head, there isn’t one so the answer is no. bricklayersoption
Nice try though. Deserves a few grams off. ethelfrida
I had a friend who was diabetic and knew a lot about blood sugar. He would tell you that watching different films burns different amounts of calories (thrillers more than romcoms I seem to remember) but doing exams burned more than any film. So, yes! JenPaws
In terms of energy usage the answer appears to be “no”, since the brain’s power draw is approximately constant and it shifts our focus when we’re concentrating with different parts of the brain being used. That may be why we tend to lose situational awareness when performing a specific task. Dorkalicious
Anecdotally, I’d say no. I find easier to keep my weight in check when I am on an easy project. I suspect the greater burning of calories, when I am on a difficult one, is more than offset by the long hours of sitting and my temporary inattention to nutrition. If there is greater burning, it must be very small indeed. SouthpawGirl
Well, I certainly lost weight when I was in a period of high anxiety, but that was due to my stomach being tied in knots and me being not being able to eat. Now I am content again, the weight has gone back on, probably a bit too much. I wish I could consciously use my brain to lose some weight, but it seems to have a mind of its own! Dunnock_Mk2
Refer to Shakespeare and Julius Caesar: “Yond Cassius has a lean and hungry look / Such men are dangerous, they think too much.” MargaretN7
