Humans are the only animals that speak human languages and can therefore a) have exploitative social relations between humans and non-humans explained to them in terms they may understand and b) be persuaded to adjust their relationship to other animals.

Human diet is not the primary problem, the industrialized slavery and murder of animals and the ignorance of/apathy to non-human suffering (not to mention the human suffering that is also a necessary consequence of that industry) that sustains that diet is.