Vegetarianism is the practice of a diet that excludes all animal flesh, including eggs, seafoods and slaughter by-products. Vegetarianism may be related to morality, religion, culture, ethics, aesthetics, environment, society, economy, politics, taste, or health. A generic term for both vegetarianism and veganism, as well as for similar diets, is "Plant-based diets". Vegetarian diets have been found to satisfy the nutritional needs for all stages of life, and large-scale studies have shown vegetarianism to increase longevity, improve health, and significantly lower risks of cancer and other diseases.

Health Concerns: Why go vegetarian?

You'll ward off disease. Vegetarian diets are more healthful than the average American diet, particularly in preventing, treating or reversing heart disease and reducing the risk of cancer. A low-fat vegetarian diet is the single most effective way to stop the progression of coronary artery disease or prevent it entirely. Cardiovascular disease kills 1 million Americans annually and is the leading cause of death in the United States. But the mortality rate for cardiovascular disease is lower in vegetarians than in nonvegetarians, says Joel Fuhrman, MD, author of Eat to Live: The Revolutionary Formula for Fast and Sustained Weight Loss. A vegetarian diet is inherently healthful because vegetarians consume no animal fat and less cholesterol and instead consume more fiber and more antioxidant-rich produce.

Religion

Hinduism and Jainism teach vegetarianism as moral conduct whilst Christianity and Islam generally do not. Buddhism in general does not prohibit meat eating, while Mahayana Buddhism encourages vegetarianism as beneficial for developing compassion.

Humans, are they supposed to be vegetarians? Quotes from the holy scriptures:

Judaism

"Behold, I have given you every herb bearing seed, which is upon the face of all the earth, and every tree, in that which is the fruit of a tree yielding seed; to you it shall be for food."

In Genesis (1:30)

"And to every beast of the earth, and to every fowl of the air, and to every thing that creepeth upon the earth, wherein there is life, I have given every green herb for food; and it was so."

Isaiah (1.11)

"He that killeth an ox is as if he slew a man."

CHRISTIANS

When Jesus spoke of meat he was talking of food Close study of the original Greek manuscripts shows that the vast majority of the words translated as "meat" are trophe, brome, and other words that simply mean "food" or "eating"

St. Luke (8:55)

Isaiah's words

"Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel. Butter and honey shall he eat, that he may know to refuse the evil and choose the good."

Hindu

The Manu-samhita, the ancient Indian code of law, states, "Meat can never be obtained without injury to living creatures, and injury to sentient beings is detrimental to the attainment of heavenly bliss; let him therefore shun the use of meat."

In another section, the Manu-samhita warns, "Having well considered the disgusting origin if flesh and the cruelty of fettering and slaying of corporeal beings, let him entirely abstain from eating flesh."

More recently the Hare Krishna movement has introduced these ethical considerations around the world. Srila Prabhupada, the movement's founder-acarya (spiritual master), once stated, "In the Manu-samhita the concept of a life for a life is sanctioned, and it is actually observed throughout the world.

Emphasizing the Vedic conception of the unity of all life, Srila Prabhupada then stated, "Everyone is God's creature, although in different bodies or dresses. God is considered the one supreme father. A father may have many children, and some may be intelligent and others not very intelligent, but if an intelligent son tells his father, 'My brother is not very intelligent; let me kill him,' will the father agree? ... Similarly, if God is the supreme father, why should He sanction the killing of animals who are also His sons?"

Islam

The Quran, 6:38

All creatures on earth are sentient beings. "There is not an animal on earth, nor a bird that flies on its wings - but they are communities like you."