Islamic dietary law permits eating the meat of halal animals—halal meaning permitted. A halal animal must be in good health, not under duress and conscious at slaughter in order for the meat from it to be halal.
Islam permits all food, except for what is prohibited in the Quran and sunnah (tradition and teachings of the Prophet). It is highly frowned upon for Muslims to be vegetarian because it goes against the tenet of the permissibility of meat in Islam. The following verse says that everything that Allah gave us is halal to eat, except that which He assigned haram.
"Eat from what Allah has given you of halal and good; give thanks to Him for his blessings if you worship Him."
—Quran, Surat an-Nahl: 114
When Muslims prohibit themselves from eating meat, they go against the following Quranic verse ordering Muslims not to characterize something as forbidden which has been made permissible by Allah.
"He only prohibited to you, the dead, blood, the flesh of pigs and whatever was offered in sacrifice to deities. So whoever eats any of these out of extreme necessity, without exceding (what is needed to sustain life), then Allah is forgiving and merciful; And do not falsely state that this is halal and that is haram, so that you may create a lie on behalf of Allah; Know that those who attach lies to Allah shall not be successful; They will be given a little bit of joy in this life, then they will have severe torment."
—Quran, Surat an-Nahl 115-117
Zabiha: Islamic slaughter