A vegetarian lifestyle is core to the Hindu belief. From the Vedas to the Shikshapatri, Hindu scriptures explain why one should refrain from eating meat and follow ahimsa or non-violence:
"You must not use your God-given body for killing God's creatures, whether they are human, animal or whatever." - Yajur Veda 12.32.90
"Ahimsa is not causing pain to any living being at any time through the actions of one's mind, speech, or body." - Sandilya Upanishad
"He who injures harmless creatures from a wish to give himself pleasure, never finds happiness in this life or the next." - Manu Samhita 5.45
"He will devour in the next world, whose flesh I eat in this life; the wise declare this to be the real meaning of the word 'flesh' [mam sah]." - Manu Samhita 5.55
"The sins generated by violence curtail the life of the perpetrator. Therefore, even those who are anxious for their own welfare should abstain from meat-eating." - Mahabharat, Anu.115.33
"He who desires to augment his own flesh by eating the flesh of other creatures, lives in misery in whatever species he may take his [next] birth." - Mahabharat, Anu.115.47
"Those sinful persons who are ignorant of actual religious principles...commit violence against innocent animals..." - Shrimad Bhagavat Puran 11.5.14
"Ahimsa is the greatest religion." - Padma Puran 1.31.27
Swaminarayan Bhagwan's first command in the Shikshapatri (verse 11) is "My devotees should not hurt any living creature and shall knowingly never even hurt small insects." Verse 12 states, "Even for the purpose of a deity or ancestral yagna (sacrificial offering), [devotees] should not kill animals like goat, deer, rabbit, or fish, because all scriptures reveal that non-violence is itself the greatest religion."
Because ahimsa is central to the Jain faith, vegetarianism is core to Jain belief as well. Sikhism does not seem to directly talk about vegetarianism, but the Adi Granth voices against animal cruelty - thus many Sikhs are vegetarian. Emphasizing compassion and ahimsa, many Buddhists are also naturally vegetarian. A large number of sects in Judaism and Christianity promote vegetarianism; even some Muslim Sufis adhere to vegetarianism.
Today, a growing number of people, especially youth, are choosing a vegetarian way of life for moral, environmental, and health reasons. Environmentally, a much larger area and much greater resources are required to grow crops for animals compared to that required for growing crops for direct human consumption.* The human anatomy and physiology suggests that humans are naturally vegetarian; for example, humans have long intestines and blunt teeth that resemble herbivores (plant-eaters) more than carnivores (meat-eaters). Due to this, colon cancer amongst many other diseases is prevalent amongst meat-eaters. Further, a vegetarian lifestyle reduces the risk of heart disease and obesity, to name just a few of the many health benefits of a vegetarian diet. The American Dietetic Association reports that "vegetarians have lower rates of death from ischemic heart disease...lower blood cholesterol levels, lower blood pressure, and lower rates of type 2 diabetes, and prostate and colon cancer." Concerned with the cruel treatment of animals, vegans do not consume dairy products or any other products that are derived from animals.
Many great leaders of the past have been vegetarians, including Pythagoras (c. 582 -507 BC), Leonardo Da Vinci (1452-1519), Ralph Waldo Emerson (1803-1882), Henry David Thoreau (1817-1862), Leo Tolstoy (1828-1910), George Bernard Shaw (1856-1950), and Albert Einstein (1879-1955). Many others have talked about such a lifestyle that supports animal rights.
*The Food and Agricultural Organization of the United Nations reports that a vegetarian diet can feed many more people than a meat-based diet. For instance, projections have estimated that the 1992 food supply could have fed about 6.3 billion people on a 100% vegetarian diet, but only 3.2 billion people on a 75% vegetarian diet.
The U.S. Department of Agriculture (USDA) estimates that the amount of water needed to produce a pound of wheat is 14 gallons while the amount of water needed to produce a pound of meat is 441 gallons; of all water used for all purposes in the United States, more than half goes to livestock production.
Another 1991 study by the USDA reports that in the United States, animals account for 70 percent of domestic grain use, while India offers just 2 percent of its cereal harvest to livestock; 80% of the agricultural land in the United States is used to raise animals for food.