Fact
Your brain is 2 per cent of your weight and 20 per cent of your energy bill
Sitting perfectly still, thinking about nothing, it is the most expensive organ you own.
An adult brain weighs around 1.4 kilograms but consumes roughly a fifth of the body’s resting energy. Most of that goes not to conscious thought but to baseline maintenance – keeping neurons ready to fire. Hard concentration adds surprisingly little on top.