This textbook for undergraduate students aims at providing an in-depth understanding of the relationship between diet, nutrients, health, diseases, and drug treatment. The book presents a comprehensive but detailed view of the field of Nutritional Biochemistry; balancing the historical with contemporary findings, the descriptive with the experimental, structure with function as well as the mechanistic and the clinical aspects of any particular nutrient. Though the major emphasis of the book is on Nutritional Biochemistry, the book also attempts to provide an insight into other related and relevant areas. Amongst the topics that are covered are: nutraceuticals, food, and nutrient interactions; the newly emerging field of the human microbiome, its interdependence on diet and human health as well as the public health concerns which is a looming burden of non-communicable diseases. Each chapter begins with an insight into the history of discovery and structure of the nutrient, its absorption, and metabolism, physiological functions, ending with diseases associated with nutrient deficiency/toxicity along with a clinical perspective. Apart from this, the book emphasizes the biochemical basis of physiological responses and correlates the same with symptoms identifying the pathophysiology. This textbook caters to students of undergraduate courses like Biochemistry, Biomedical Sciences, Biological Sciences, Life Sciences, Home Science; Nutrition and Dietetics, Clinical Nutrition and Dietetics, and Nursing.