That's cute, but partially false, and is the main reason animals eating other animals exists.

Obligate carnivores, as an example, eat other animals not as a shortcut to the diets of the other animals, but because the other animals' livers manufacture amino acids that the obligate carnivores' livers do not.

Should be "You are what what you eat eats."

Chaining more also works nicely: "You are what what what you eat eats eats," or, "You are what what what what what what you eat eats eats eats eats eats," and so on. All of which are true in some small proportion, of course.