A brain friendly diet has some does and some don'ts. Read the Vitamins thread. It was prescribed to me by an ortho-molecular psychiatrist 30 years ago to help me with a drug free recovery from severe depression. In 8 weeks, I was a new man.

If you have a sweet tooth, limit it to sugar sweetened dark chocolate if possible. Dark chocolate has some brain friendly components.

The fats in pork are the best for the brain. It has the best BCAA's Broken Chain Amino Acids.
The unprocessed fat from coconut is also good. It has MCTs, Medium Chain Triglycerides.

Stay away from processed fats and processed or modified sugars.