The sattvic diet is followed most strictly by renunciants, yogis and ascetics for whom diet is one tool among several for training the mind toward meditation, and it shapes the kitchens of many temples and Vaishnava households, where food offered to a deity is prepared and eaten as prasad under sattvic principles. It overlaps heavily with the vegetarianism already widespread among Hindus on grounds of ahimsa, nonviolence, but it is a narrower and more specific standard: a vegetarian meal built around chili, garlic, onion and deep frying would still count as rajasic or tamasic rather than sattvic.
Observance outside monastic and temple settings is a matter of degree rather than an obligatory rule binding on every Hindu. Many householders adopt sattvic eating for a fast, a festival, or a period of spiritual practice, rather than as a permanent standard, and the diet has also traveled outward through the modern popularity of yoga, where it is often taught as a wellness practice loosely detached from the guna theory that originally explained it. The classification is followed in practice as much as in theory: fresh fruit, milk, ghee, whole grains, legumes and mild vegetables are the standard sattvic staples, while onion, garlic, meat, alcohol, and heavily fried or long-stored food are set aside as rajasic or tamasic. ISKCON and other Vaishnava movements built entire kitchens around the standard so that food offered to the deity, and afterward eaten by devotees as prasad, meets it without exception, and the same vocabulary now circulates well beyond any temple through the modern yoga and wellness market, where sattvic eating is often taught as a general lifestyle choice loosely detached from the guna theory that originally explained it.