This is a multi-author book, attempting to meet the demand for such a work from students, teachers, research scientists and professionals from disciplines of medicine, public health, home science, biology, nutrition and dietetics, agriculture and others where nutrition is an important subject. This edition is dedicated to late Dr C Gopalan, an outstanding nutrition scientist of world eminence who passed away at the age of 100 on October 3, 2019. The multi-disciplinary science of nutrition transcends many boundaries in science and hence the book will be of interest not only to nutritionists and nutrition scientists, but also to the professionals in the fields of food chemistry, agriculture, medicine, public health, modern biology and many others, besides planners and policy makers. The chapters are devoted to basic, clinical and applied subjects like chemical nature, physiology and metabolism of nutrients (Section I), assessment of nutrition status and nutrient requirement (Section II), functional significance of nutrition (Section III), nutritional deficiency disorders (Section IV), dietary nutrition and degenerative diseases (Section V), food safety (Section VI), and reaching nutrition to the community including climate change (Section VII).