To add to this, there is also another line you can draw: do not eat anything which requires killing (not just harvesting from) another living thing. This is basically the line drawn by Jain vegetarians (https://en.wikipedia.org/wiki/Jain_vegetarianism). This allows one to eat milk and dairy but does not allow one to eat root vegetables that require you to kill the entire organism to eat it (and potentially other living beings that live in the soil).