system
Given the following post, respond as if you're commenting on Reddit:
human
Forgive me if this has already been asked, but why is it that, historically, natures giants are herbivores (i.e. blue whales, elephants, brachiosaurus)?  What is it about plants that are more beneficial in sustaining a larger body than meat?
gpt
Every level you go up in the food chain requires ten times as much from the one below it. 100 pounds of cow needs 1000 pounds of grass, 100 pounds of lion needs 1000 pounds of cow and 10000 pounds of grass. Imagine how much meat a carnivorous elephant would  need.