Brain fuel and Kryptonite

Great for the munchies, but simple carbs like candy burn quickly like paper on fire. Image thanks to JANA KOLLAROVA.

The brain’s fuel is sugar, which is not license to load up on Coke thinking it will make your brain superpowered and impervious to fatigue unless we find hitherto untapped sources of Kryptonite. Sorry.

The brain needs glucose, which it gets from the food we eat. And it’s hungry. Really hungry. In fact it’s disproportionately hungry.

In terms of its size relative to the rest of the body, the brain is pretty small. Ok, in some people, it seems smaller than what it actually may be, but that’s another post. On average, it’s comfortably less than 2% of body weight. But for its size, it consumes colossal amounts of glucose, as much as up to 20% of what your body has.

Ever wondered why thinking can make you tired? Now you know. Brain work, thinking, is effortful, and requires energy, just like other activities do. But it’s the particular activity of the brain that makes it so hungry.

Your brain is always active, somewhere, somehow. Even when you’re resting, or sleeping, the brain works. This all requires fuel. The more work you’re giving it to do, such as concentrating hard, the more energy it requires. A slightly more impressive way of saying this is that metabolic activity requires energy resources.

And the way the brain communicates, and the work it has to do, taxes your glucose reserves. Naturally, as we deplete reserves, we have to replenish them.

Remember how in the last post we talked about the postprandial dip and how, as you feel yourself wilting, there’s a temptation to look for stimulants, often in the form of sugar? The circadian rhythm component can be exacerbated by diminishing energy reserves after a morning’s hard thinking. Double whammy.

So here’s the take home bit

We want sugar because we’re tiring and it’s a stimulant, and also because we’ve used up our reserves and they need replenishing. If we’ve got hard thinking still to do, try

  • taking a short exercise break for five minutes to invigorate yourself. Go up and down the stairs perhaps, or to the corner and back.
  • eating good food for your glucose, rather than not so good food. Opt for complex carbs that you find in natural foods, rather than simple carbs that you find in processed food.
  • thinking about it like a fire. Simple carbs are like putting paper on a fire, they burn quick. Complex carbs are like putting coal on, they burn slow. Go with the slow.
  • Give your kids lunch that will get them through the afternoon

Impressive words to drop into the morning coffee chat

Metabolic activity

What have you noticed?

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About brendonbclark

Hi, I’m Brendon, but people usually call me B. I’ve a Masters degree in psychology, postgraduate qualification in mental health, and qualifications in counselling, professional supervision and adult education. I consult, speak and blog. Join me, you can subscribe for free.
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