Why does a vegetarian leave a smaller ecological footprint than a person who eats meat? a. Vegetarians need to ingest less chemical energy than omnivores. b. Fewer farm animals are slaughtered for human consumption. c. Vegetarians require less protein to sustain life than do omnivores. d. Eating meat is an inefficient way to utilize autotrophic productivity e. There is an excess of plant biomass in all terrestrial ecosystems.