Within Vaishnavism, diet is understood as an extension of devotion itself, shaped by the principles of ahimsa (non‑violence), purity of consciousness, and the offering of food to Vishnu or his avatars before eating. The standard is a strictly lacto‑vegetarian way of life: meat, fish, eggs, and any products derived from animals that were harmed or killed are avoided, while dairy from cows is accepted and often regarded as especially sacred. This vegetarianism is not merely a health choice but a deliberate spiritual discipline, intended to minimize harm to other beings and to avoid the karmic consequences associated with killing. In many communities, there is also a strong emphasis on ritual cleanliness in cooking and on maintaining a kitchen environment that supports a devotional mood.

A central practice is that food is prepared with reverence and then offered to Vishnu or Krishna before being consumed, at which point it is regarded as prasada, sanctified food that nourishes both body and consciousness. The inner attitude while cooking and offering is considered as important as the ingredients themselves, since the goal is to transform ordinary eating into an act of worship. This understanding helps explain why many Vaishnavas are careful about where food comes from and how it is obtained, avoiding anything linked to unethical behavior or exploitation.

In terms of specific restrictions, many Vaishnavas avoid onions, garlic, mushrooms, and certain other items that are classified as rajasic or tamasic, that is, foods thought to stimulate passion or dullness and thereby disturb meditation and devotional focus. Alcohol and other intoxicants are rejected for the same reason: they cloud awareness and are seen as obstacles to steady remembrance of the divine. Some traditions also speak of avoiding particular vegetables or spices that are considered less pure, though the exact list and strictness can vary by region and lineage. Alongside these avoidances, there is a clear preference for fresh, simple, sattvic foods such as fruits, vegetables, grains, legumes, nuts, and dairy products.

Across different Vaishnava sampradayas, these principles are interpreted with some variation, yet the underlying pattern remains consistent: food is chosen and prepared so that it supports clarity of mind, gentleness of heart, and constancy in devotion. The plate becomes a kind of altar, and the act of eating becomes a continuation of worship, guided by non‑violence, purity, and the desire to live in a way that is pleasing to Vishnu and his devotees.