According to Vedic Scriptures meat eating is prohibitive as any non-vegetarian diet (meat/fish/egg ) is simply an attachment of the tongue. In every religion, killing is prohibitive or very much restricted. In the Christian religion you have the commandment “Thou shalt not kill.” However, today nearly everyone is violating this commandment. If you violate the injunction given by Lord Jesus Christ, how can you claim to be Christian. And even if one is not a Christian, killing is most sinful and should be avoided as far as possible. By killing you become entangled in sinful activities and their resulted reactions, as a result, we will have to take various types of bodies, perpetually. Sometimes people argue that vegetables also have life. Yes, this is true and that is why it is recommended in the scriptures to eat only prasadam, food offered to Kṛṣṇa before being eaten. Whatever Kṛṣṇa leaves, we should take. This is the process according to Vedic Scriptures, We should’t take directly. So, while the vegetables have life, Kṛṣṇa says, patram puspam phalam toyam yo me bhaktya prayacchati tad aham…asnami: [Bg. 9.26] ” If one lovingly offers me a leaf, a flower, or water, I will accept it.” Then there is no sin in eating vegetables.
Source: A.C. Bhaktivedanta Swami Prabhupada (2014 edition), “The Quest for Enlightenment”, Page 71, 72 & 186
A.C. Bhaktivedanta Swami Prabhupada (2014 edition), “The Science of Self-Realization”, Page 133