What are you eating mentally?

We all need food to live.
But what you eat matters, if you eat healthy, your body will work better than if you were to eat unhealthily, as an example, if you eat only chocolate cake every day twice a day, you would be dead very quickly, but in eating healthily your body gets the nutrients it needs to function properly.
The same can be said for the mind (Excluding fish which is actually good for your mind), If it is filled with unnecessary “junk food”, it will not function or think properly, but fill it with a well rounded meal on a regular bases, and you develop a healthy mind.