"You are what you eat." You might have heard this phrase at some time in your life.   It comes from a French phrase from 1826, "Dis-moi ce que tu manges, je te dirai ce que tu es." [Tell me what you eat, and I will tell you what you are].  Slightly different, but you get the point. "You are what you eat" originated with an idea in Europe in 1800 that "the food one eats a bearing on one's state of mind and health." Well, people in 1800 were correct.  There is more and more evidence that food can have an impact on your mental health.