Perhaps the most sophisticated Upanishadic food framework is the classification of all foods according to the three gunas — fundamental qualities that permeate all of existence. Sattvic foods (fresh fruits, vegetables, whole grains, dairy) promote clarity, peace, and spiritual openness. Rajasic foods (heavily spiced, stimulating, or excessively salty dishes) generate restlessness, ambition, and agitation. Tamasic foods (stale, overly processed, or excessively heavy foods) produce dullness, lethargy, and confusion. This system predates modern nutritional science by thousands of years, yet it maps with striking accuracy onto contemporary research on anti-inflammatory diets, the cognitive effects of ultra-processed foods, and the gut microbiome’s influence on mental states.