The never ending argument which speaks of which diet is better than the other comes to an end, as we tell you which is better and why.
Not only Jainism practices strict vegetarianism based on the principle of non violence, they also avoid unnecessary injury to other living things; the aim being causing no harm to any other living specie in the world. Any act that supports killing or injury to any living organism, add upto your sins. This sect of the society considers every living organism as equal, which is why killing is strictly banned in this religion.
When Hinduism talks of non violence, it speaks of the karmic effects of both human and animal action. The Bhagavata Purana and the traditional book of Hindus, Manusmriti, strictly condemns the slaughter of animals for personal good. Mentioned in Hindu scriptures is the question of religios dutires of humans towards others living species and that of why killing them is a matter of negative karma.
Sikh Gurus, since centuries, have also indicated their preference for a simple vegetarian diet. The holy book of Sikhs, Guru Granth Sahib, mentions that overconsumption of food involves a drain of natural resources of earth and indirectly of life. The tenth guru of Sikhs, Guru Gobind Singh, prohibited the Sikhs from the consumption of any ritually or otherwise slaughtered meat.
Few sects of Islam and Christianity, prohibits the consumption of any kind of meat. In Islam, especially the followers of Sufism, following a strictly vegetarian diet is mandatory. Eastern Christianity generally follows veganism, if not vegetarianism. There is a stand in the ethical teaching of Jesus, about mercy towards the weak.