Vegetarianism

[Afgun]

There is no suggestion in the Qur'an Majeed or in any other of the Islamic sources that eating meat is good for physical or spiritual health. Islam's approach in this matter is neutral; it has left the choice to the individual, but those who opt to eat meat are urged in the Qur'an Majeed to eat in moderation. (The Qur'an 7:31; 5:87 and other verses). Furthermore, there are elaborate and stringent laws governing the ove rall treatment of animals used for food - their rearing and breeding; the pre-slaughter; and handling during and after slaughter.
The Holy Prophet(s) has placed the killing of animals without a justifiable reason as one of the major sins:

Avoid ye the seven obnoxious things {deadly sins}: polytheism; magic; the killing breathing beings! Which God has forbidden except for rightful reason. (Narrated by Abu Huraira. Sahih Mulim - Kitab-ul-Imam (Ref. No. 46); Chapt. XXXIX, Vol.I; p. 52. Bukhari, 4:23. Also Awn, (Ref. No. 32); Hadith No. 2857.

The Arabic word for 'breathing beings' is 'Nafs.' Until recently it used to be taken as meaning 'human beings' only. All the Arabic dictionaries give the meaning of 'Nafs' as 'Ruh' (soul), and since they are breathing creatures, there seems to be no reason why the Qur'anic verses No. 6:151, 152 and others should not comprehend all 'breathing beings', i.e. all species of animals. These verses should be read in conjunction with other verses of the Qur'an Majeed and numerous Ahadith which speak of the sanctity of life as a whole, declare animals as possessing soul (zi Ruhin) and place animals physically on a par with human beings.

The baneful {sinful} things are: polytheism; disobedience to parents; the killing of breathing beings without a valid reason.
(id. Narrated by Abdullah Ibn 'Amr.)