Advanced nutritional science explores how nutrients interact with cellular systems, metabolism, and whole-body physiology to influence health and disease. The book integrates detailed chapters on macronutrient and micronutrient metabolism, endocrine regulation, gut microbiome interactions, and nutrigenomics. Methodological sections describe biomarker discovery, metabolomics approaches, and clinical trial designs for nutrition research. Translational chapters examine how mechanistic insights inform dietary guidelines, therapeutic nutrition, and public-health policy. Readers also find critical discussions on assessing causality, heterogeneity in dietary responses, and research ethics. Geared toward researchers, clinical nutritionists, and graduate students, it bridges cutting-edge science with applications for health promotion.