Chess, a clear head and food

Like sporters use special diets to enhance their performance I have found that what I eat and drink has a great effect on my clarity of thinking, alertness and concentration. I wonder if professional chess players prefer certain foods in this respect.

I know that taking food supplements -> minerals, vitamins and neurotransmitters which I take daily (the so called smartdrink) improve my chess gaming or rather, as I did an experiment these last two weeks, NOT taking them made me play worse as people can see by checking my games and ratings. I was a lot number and less creative in my thinking, as if there was a wall there that blocked me in finding a strategic or tactical move.

I know alcohol has a devastating effect on the ability to play chess, but maybe for some people it could be advantageous to drink a few beers when playing?

So have people experience with the relation between food and clearheaded thinking?

Weed is my PED of choice...

I won't contradict you. What is a PED?

got it: https://en.wikipedia.org/wiki/Performance-enhancing_substance