"My doctor has told me I should not take in as much potassium as I have been so I am reducing my consumption of legumes" and "I have an ethical objection to killing sentient creatures so I restrict my diet in ways that minimize such killing"
Are both sound, rational judgements which do not require a peer reviewed paper.
>You(sic) vegan foodstuff also require the killing of sentient creatures - to grow food we have displaced a lot of animals from their habitats. Sometimes quite forcefully. So yeah - you probably have fewer animals on your conscience , but you have some.
I agree with you, completely - it is an uphill battle. It is very difficult to not directly compensate the killing of creatures in a world that considers it moral to kill 50+ billion animals every year (not including marine life) - but my ethics require that I at least try.