Your brain is at its biggest just before breakfast
After a long day, your muscles may be tired, some joints may ache, but your brain is positively exhausted. Even at rest, this precious organ is thought to be burning a minimum of 10.8 calories per hour while undergoing various chemical changes at the same time. Concentrating on tasks becomes harder throughout the day. Your willpower to avoid unwanted habits or choices is challenged. And of course, your brain is simply smaller by the time you’re ready for bed. Wait, what?
Your brain may be up to 77% water by weight, and as the day goes on your brain seems to actually dry up a bit. If you think of it like a sponge, a reduction of fluids means the brain itself shrinks slightly as it “drys.” When you lie down to sleep at night, those fluids are redistributed, plumping your brain back up.
This is not to say that your brain will find itself rattling around in your skull by 11pm, as the change in size is very small. It’s more significant as a variable to control for when studying brains for diseases like Alzheimers, so that changes in brains aren’t misattributed. It also adds to the growing body of evidence that our brains undergo crucial maintenance when we sleep, helping to avoid things like increased to uncontrolled excitability, which at its most extreme can lead to seizures.
So give your brain a chance to rest, do some “garbage collection,” and apparently, take a nice bath to soak in each night.
Source: Your Brain Is Bigger In The Morning, Neuroskeptic