"not to much" is maybe the core of a healthy diet, and very underrated nowadays. "Hunger is a big problem in most empoverished parts of the world. Bu today, in western countries, we can say with certainty, that much more people are sick by the excess of food than by not eating enough" --Max Heindel. I don't remember the quote exactly, but It is something like this.

Why mostly plants? Disregarding the animal's health, eating meat appears to me as logically non-toxic while many plants do contain toxins.