Many Hindus affirm that a vegetarian diet is preferable, and for some castes and communities obligatory, as an expression of ahimsa, non-harm to living beings. The ideal is bound up with the classification of foods as sattvic (pure, conducive to clarity), rajasic (stimulating), and tamasic (dulling), with vegetarian, freshly prepared food counted sattvic and meat generally reckoned rajasic or tamasic. Brahmins and many devotional and ascetic communities have long kept vegetarian, and the value is reinforced by the sacredness of the cow and by traditions of non-violence.
The Manusmriti, a foundational law text compiled in the early centuries CE, condemns the eating of meat obtained by killing yet permits it in specific ritual contexts such as ancestral offerings (shraddha), reflecting an old tension between prescribed sacrifice and the growing ideal of non-harm. Vaishnava movements built strict vegetarianism into devotional practice: the International Society for Krishna Consciousness (ISKCON), founded in 1966, requires it of initiated members as inseparable from prasadam, food first offered to Krishna and only then eaten as blessed remnant, so that what is eaten and how it is prepared both matter religiously. By contrast, some Shakta and Tantric Shaiva traditions historically practised animal sacrifice, and communities such as the Kalikula worshippers at Kolkata's Kalighat temple continue goat sacrifice to the Goddess today, defended on different theological grounds from the Vaishnava emphasis on non-harm.