Our current scientific understanding in no way leads to such a conclusion.
However, even considering the hypothetical that plants are sentient, eating plants actually causes the least harm seeing as livestock are not very efficient converters of plants to meat.
>eating plants actually causes the least harm seeing as livestock are not very efficient converters of plants to meat.
Let's continue this facile logic to it's conclusion: if animals are causing so much "harm", why shouldn't we kill them to prevent them from "harming" so much?
Plants are sentient creatures