The practice of vegetarianism is strongly linked with a number of religious traditions worldwide. These include religions that originated in India, such as Hinduism, Jainism, Buddhism, Sikhism and Taoism. With close to 85% of India's billion-plus population practicing these religions, India remains the country with the highest number of vegetarians in the world.

In Jainism vegetarianism is mandatory for everyone; in Hinduism and Mahayana Buddhism it is promoted by scriptures and religious authorities but not mandatory. In the Abrahamic religions (Judaism, Christianity and Islam) and the Bahá'í Faith, vegetarianism is less commonly viewed as a religious obligation, although in all these faiths there are groups actively promoting vegetarianism on religious and humanitarian grounds, and many other faiths hold vegetarian and vegan idea among their tenets.

Religions originating in the Indian subcontinent

Jainism institutes an outright ban on meat. The majority of Indians eat meat and only about 30% of India's 1.2 billion population practises lacto-vegetarianism.

Jainism

Vegetarianism in Jainism is based on the principle of nonviolence (ahimsa, literally "non-injuring"). Vegetarianism is considered mandatory for everyone. Jains are either lacto-vegetarians or vegans. No use or consumption of products obtained from dead animals is allowed. Moreover, Jains try to avoid unnecessary injury to plants and sūkṣma jīva (Sanskrit for 'subtle life forms'; minuscule organisms). The goal is to cause as little violence to living things as possible, hence they avoid eating roots, tubers such as potatoes, garlic and anything that involves uprooting (and thus eventually killing) a plant to obtain food.

Every act by which a person directly or indirectly supports killing or injury is seen as violence (hinsa), which creates harmful karma. Ahimsa aims to prevent the accumulation of such karma.Laidlaw, James: Riches and Renunciation. Religion, economy, and society among the Jains, Oxford 1995, p. 26–30, 191–195. Jains consider nonviolence to be the most essential religious duty for everyone (ahinsā paramo dharmaḥ, a statement often inscribed on Jain temples). Their scrupulous and thorough way of applying nonviolence to everyday activities, and especially to food, shapes their entire lives and is the most significant hallmark of Jain identity. Jains do not practice animal sacrifice as they consider all sentient beings to be equal.

Hinduism

Hinduism has a wide variety of practices and beliefs that have changed over time. Only some sects of Hindus observe vegetarianism, an estimated 33% of all Hindus are vegetarians.

Nonviolence

The principle of nonviolence (ahimsa) applied to animals is connected to avoid negative karmic influences which result from violence. The suffering of all beings is believed to arise from craving and desire, conditioned by the karmic effects of both animal and human action. The violence of slaughtering animals for food, and its source in craving, reveal flesh eating as one mode in which humans enslave themselves to suffering.Walters, Kerry S. and Portmess, Lisa. Religious Vegetarianism: From Hesiod to the Dalai Lama. State University of New York Press. New York, 2001. pp. 41, 42, 61, 62, 187, 191. . Hinduism holds that such influences affect the person who permits the slaughter of an animal, the person who kills it, the person who cuts it up, the person who sells it, the person who buys it, the person who cooks it, the person who serves it up, and the person who eats it. They must all be considered the slayers of the animal. The question of religious duties towards the animals and of negative karma incurred from violence (himsa) against them is discussed in detail in Hindu scriptures and religious law books.

Hindu scriptures belong or refer to the Vedic period which lasted till about 500 BCE according to the chronological division by modern historians. In the historical Vedic religion, the predecessor of Hinduism, meat-eating was not banned in principle, but was restricted by specific rules. Several highly authoritative scriptures bar violence against domestic animals except in the case of ritual sacrifice. This view is clearly expressed in the Mahabharata (3.199.11–12;Mahabharata 3.199 is 3.207 according to another count. 13.115; 13.116.26; 13.148.17), the Bhagavata Purana (11.5.13–14), and the Chandogya Upanishad (8.15.1). For instance, many Hindus point to the Mahabharata's maxim that "Nonviolence is the highest duty and the highest teaching,"Mahabharata 13.116.37–41 as advocating a vegetarian diet. The Mahabharata also states that adharma (sin) was born when creatures started to devour one another from want of food and that adharma always destroys every creature "Mahabharata section LXVI" It is also reflected in the Manu Smriti (5.27–44), a traditional Hindu law book (Dharmaśāstra). The Kural, a c. 5th-century-CE secular text of Hindu or Jain origin, insists on moral vegetarianism or veganism. These texts strongly condemn the slaughter of animals and meat eating.

The Mahabharata (12.260;Mahabharata 12.260 . Mahabharata 12.260 s 12.268 according to another count. 13.115–116; 14.28) and the Manu Smriti (5.27–55) contain lengthy discussions about the legitimacy of ritual slaughter and subsequent consumption of the meat. In the Mahabharata both meat eaters and vegetarians present various arguments to substantiate their viewpoints. Apart from the debates about domestic animals, there is also a long discourse by a hunter in defence of hunting and meat eating.Mahabharata 3.199 . Mahabharata 3.199 is 3.207 according to another count. These texts show that both ritual slaughter and hunting were challenged by advocates of universal non-violence and their acceptability was doubtful and a matter of dispute.Alsdorf pp. 572–577 (for the Manu Smriti) and pp. 585–597 (for the Mahabharata).

Lingayats are strict vegetarians. Devout Lingayats do not consume beef or meat of any kind including fish.

Modern day In modern India the food habits of Hindus vary according to their community or caste and according to regional traditions. Hindu vegetarians usually eschew eggs but consume milk and dairy products, so they are lacto-vegetarians. According to a survey from 2006, vegetarianism is low in coastal states and high in landlocked northern and western states and among Brahmins in general, 85% of whom are lacto-vegetarians. In 2018 a study in Economic and Political Weekly showed that as few as one-third of upper-caste Indians could be vegetarian.

Many coastal inhabitants are fish-eaters. In particular, Bengali Hindus have romanticised fishermen and the consumption of fish through poetry, literature, and music. Hindus who eat meat are encouraged to eat Jhatka meat.

Animal sacrifice in Hinduism Animal sacrifice in Hinduism (sometimes known as Jhatka Bali) is the ritual killing of an animal in Hinduism. The majority of the sects of Hinduism like Vaishnavas, Shaivas, Smartas, Swaminarayan, Lingayat, Ganapatya, and so forth condemn animal sacrifice and consider it a sin. Only Shakta tradition has a custom of animal sacrifice. The ritual sacrifice normally forms part of a festival to honour a Hindu god. For example, in Nepal the Hindu goddess Gadhimai is honoured every five years with the slaughter of 250,000 animals. This practice was banned from 2015. Bali sacrifice today is common at the Sakta shrines of the Goddess Kali. However, animal sacrifice is illegal in India.

Buddhism

The First Precept prohibits Buddhists from killing people or animals. The matter of whether this forbids Buddhists from eating meat has long been a matter of debate, however, as vegetarianism is not a given in all schools of Buddhism. The first Buddhist monks and nuns were forbidden from growing, storing, or cooking their own food. They relied entirely on the generosity of alms to feed themselves, and were not allowed to accept money to buy their own food. They could not make special dietary requests, and had to accept whatever food alms givers had available, including meat.

Monks and nuns of the Theravada school of Buddhism, which predominates in Sri Lanka, Thailand, Cambodia, Burma, and Laos, still follow these strictures today. These strictures were relaxed in China, Korea, Japan, and other countries that follow Mahayana Buddhism, where monasteries were in remote mountain areas and the distance to the nearest towns made daily alms rounds impractical. There, Buddhist monks and nuns could cultivate their crops, store their harvests, cook their meals, and accept money to buy foodstuffs in the market.

According to the Vinaya Pitaka, when Devadatta urged the Buddha to make complete abstinence from meat compulsory, the Buddha refused, maintaining that "monks would have to accept whatever they found in their begging bowls, including meat, provided that they had not seen, had not heard, and had no reason to suspect that the animal had been killed so that the meat could be given to them". There were prohibitions on specific kinds of meat: meat from humans, meat from royal animals such as elephants or horses, meat from dogs, and meat from dangerous animals like snakes, lions, tigers, panthers, bears and hyenas.

On the other hand, certain Mahayana sutras strongly denounce the eating of meat. According to the Mahayana Mahaparinirvana Sutra, the Buddha revoked this permission to eat meat and warned of a Dark Age when false monks would claim that they were allowed meat. In the Lankavatara Sutra, a disciple of the Buddha named Mahamati asks "[Y]ou teach a doctrine that is flavoured with compassion. It is the teaching of the perfect Buddhas. And yet we eat meat nonetheless; we have not put an end to it." An entire chapter is devoted to the Buddha's response, wherein he lists a litany of spiritual, physical, mental, and emotional reasons why meat eating should be abjured. However, according to , this chapter on meat eating is a "later addition to the text....It is quite likely that meat-eating was practiced more or less among the earlier Buddhists, which was made a subject of severe criticism by their opponents. The Buddhists at the time of the Laṅkāvatāra did not like it, hence this addition in which an apologetic tone is noticeable." points to a passage in the Surangama Sutra which implies advocacy of "not just a vegetarian, but a vegan lifestyle"; however, numerous scholars over the centuries have concluded that the Śūraṅgama Sūtra is a forgery. Moreover, in the Mahayana Mahaparinirvana Sutra, the same sutra which records his retraction of permission to eat meat, the Buddha explicitly identifies as "beautiful foods" honey, milk, and cream, all of which are eschewed by vegans. However, in several other Mahayana scriptures, too (e.g., the Mahayana jatakas), the Buddha is seen clearly to indicate that meat-eating is undesirable and karmically unwholesome.

Some suggest that the rise of monasteries in Mahayana tradition to be a contributing factor in the emphasis on vegetarianism. In the monastery, food was prepared specifically for monks. In this context, large quantities of meat would have been specifically prepared (killed) for monks. Henceforth, when monks from the Indian geographical sphere of influence migrated to China from the year 65 CE on, they met followers who provided them with money instead of food. From those days onwards Chinese monastics, and others who came to inhabit northern countries, cultivated their own vegetable plots and bought food in the market. This remains the dominant practice in China, Vietnam, and part of Korean Mahayanan temples.

Mahayana lay Buddhists often eat vegetarian diets on the vegetarian dates (齋期 zhāi qī). There are different arrangement of the dates, from several days to three months in each year, in some traditions, the celebration of the bodhisattva Avalokitesvara's birthday, enlightenment and leaving home days hold the highest importance to be vegetarian.