Impact of Diet on Brain Size

Vegetarians have smaller brains.

This is seen in humans, that the less a human eats meat,

then the smaller the brain becomes.

The brain is so dependent on the nutrient density that comes from animal sourced

foods that it will suffer when it doesn't get them. It's a real thing.

And why does depression go up so much when

people stop eating animal sourced foods?

It's because you are depriving the brain of what it needs.