We are materially nothing but spiritually everything. We the human being is called the best creature of all the creatures made by GOD, the Almighty but to nature fury, we are wiped out by a twinkling of an eye that we have got proof during Tsunami.
See a normal person wont be able to use 100% of brain. Only spiritually we can make use of our brain. If we started using 100% than we are almost god!!
Do we get hungry when we use our brain too much?
We should. Any bodily process requires energy. Thinking is absolutely no exception. And our body makes it a priority to get food to our brain first because it's that important. After all, our brain also controls essential bodily functions such as breathing and heart beat. If it lacks the capacity to do that, then we die.
Our brain cells like any other cell in your body needs energy. When we think, at a molecular level, our brain cells are sending electric impulses.
So we're going to need food in order to constantly send electric impulses and think.