The interwebs tells me that the human body burns between 90-110 calories per hour when idle. We all know that actually getting off your fat fucking arse and exercising is the best way to burn calories, but I wonder why I can’t find anything about how many calories are burned by thinking.
At a basic level I assume that a brain works like a CPU, when it’s gunning at 100% usage it heats up and uses more power than it does when idle. Surely a brain is the same? Staring slackjawed at Gladiators on TV must burn less calories than solid concentration on mathematical problems.
Google is contaminated by thousands of websites that discuss ‘thinking yourself thin’ and the mental attitude required to lose weight, so I can’t find anything that mentions any actual research that gives a clue as to what bearing sheer thought has on calorific burn. I managed to find a couple of Yahoo! questions, but all of the answers are unscientific opinions by individuals who don’t quote sources. Those people say the effect of thinking is miniscule, but given the lack of evidence I’m not going to accept that as fact.
Is this why the archetypal nerd is thin and gangly? I read or watched something (can’t remember where, it’s very unscientific of me) which stated that a weight variation of half a stone can be affected by as little as 7 calories per day over the course of a year. While that might sound a bit improbable, it could certainly explain why ‘smarter’ people who use their brains more are generally thinner, because the brain really wouldn’t need to burn very many more calories per day in order to affect the weight of a person over a sufficiently long time period. Over the course of your life, the possible impact cannot be ignored.
Obviously there are limits to this theory. If your eating pattern is variable or you’re just a fat git, working your brain won’t make much visible difference because there are too many other factors in play. But, if you’re an average person who eats a fairly consistent amount of food, it makes utter sense that someone who taxes their brain with complex and profound thoughts will weigh less than someone who, say, reads the Daily Mail.
Given the multitude of studies and news articles that bang on about weight loss factors, I wonder why this hasn’t got a scientific footnote somewhere. Suffice to say if you, person reading this, have any idea or can quote me a study, I’d be very interested to read it.
Now I’ve written all that, I’m sure I’ve burned at least enough to justify a small ice cream. 🙂
Update: http://answers.google.com/answers/threadview?id=381608 – some answers!
Interesting reading, it looks like this is indeed the case, although most calories are burned when learning something new, rather than engaging mentally in something you already know.