Ancient hippies subsisted on a diet of nuts and berries. They did so because meat was hard to find, harder to track, and even harder to kill, whereas nuts and berries proved to be a far more sedentary prey. Basically it wasn't so much that the hippies felt a kinship with all living things; it was more that they were really lousy hunters.

Modern hippies tend to subsist on a diet of nuts and berries as well, but for reasons which make much less sense.