As one example, Jainism forbids meat eating and has done since 6th century bc.
Hinduism and Buddhism also advocate abstinence which is interpreted more or less strictly depending on the school.
Over 350 million people in India alone are vegetarians due to religious influence.
Why? The reasons could be manifold.
The souls incarnating in these societies may have had pre-incarnation a strong bias towards aggression or war like behaviour.
The environment may not have been sustainable for the duration of the cycle had the population been carnavores.
The amount of souls wishing to incarnate in this society would be too great a burden if they were meat eaters.
Hinduism and Buddhism also advocate abstinence which is interpreted more or less strictly depending on the school.
Over 350 million people in India alone are vegetarians due to religious influence.
Why? The reasons could be manifold.
The souls incarnating in these societies may have had pre-incarnation a strong bias towards aggression or war like behaviour.
The environment may not have been sustainable for the duration of the cycle had the population been carnavores.
The amount of souls wishing to incarnate in this society would be too great a burden if they were meat eaters.