Hawzah News Agency (Qom, Iran) - Grand Ayatollah Nasser Makarem Shirazi, a Shia source of emulation, answers an inquiry about eating meat and vegetarianism:

Question: What is Islam’s view about eating meat and vegetarianism?

Grand Ayatollah Makarem: Eating excessive amount of meat is inappropriate in Islam, not eating meat up to 40 days has also been prohibited; and we have found out through experience that the human being is healthier by eating vegetables and eating less meat.