"You need to be starved and in need to get maximum of your brain capacity."
Are you serious? It's when I haven't eaten enough in hours that my "brain capacity" gets to an all-time low. Observe how nothing ever really gets Done in societies with extended periods (ie. days or weeks) of fasting during that period. Go to those impoverished areas of the world where people still suffer from hunger and ask them about how their brain capacity is at a maximum. Human beings need food, news at eleven.
It is a very big subject. Fasting is a way of training self-will and conquering yourself. It is long and difficult process.
And it is not just about energy or calories. There is also spiritual part.
Think about sublimation as a greatest source of power and will.
You need to be starved and in need to get maximum of your brain capacity. Or think about visiting an unfamiliar place (city, country) how you became sharp and alerted.
So, nothing special. Just pathetic.