Dinacharya (daily regimen), Ritucharya (seasonal regimen), and Sadvritta (code of ethical/behavioral conduct) constitute the three principal lifestyle-based pillars of Swasthavritta, the Ayurvedic discipline of preventive and social medicine. This review examines the convergence between these classical constructs and contemporary biomedical evidence in chronobiology, seasonal metabolic/immune physiology, and behavioral/positive psychology. Dinacharya\\\'s alignment with circadian biology is the best-substantiated of the three, supported by molecular chronobiology (201 7 Nobel Prize-recognized clock genes) and clinical chronodisruption data. Ritucharya\\\'s seasonal-adaptation framework corresponds to documented seasonal variation in gene expression, gut microbiome composition, and metabolic markers, though direct outcome trials specific to Ritucharya remain limited. Sadvritta\\\'s ethical-conduct framework parallels established constructs in positive psychology (prosocial behavior, self-regulation, gratitude, compassion) with plausible but under-quantified mental-health impact. Collectively, these three pillars represent a coherent, low-cost, non-pharmacological framework for public health promotion and NCD prevention, though the evidence base is dominated by narrative/conceptual reviews rather than controlled outcome trials — a gap this paper identifies as the priority for future research.