As you all know that nutrition is the core of human health. The type of diet in everday life, we eat has a direct and significant impact on our health. Eating a healthy balanced diet improves the quality of our life, whereas a poor diet may lead to morbidity and disease. This book has been divided into two units. Unit I provides comprehensive overview of basic principles of meal planning, use of food pyramid in meal planning, RDAs, food exchanges, balanced diets for various age groups and nutrition across human life span. Different aspects of normal human nutrition i.e. foods and nutrients required and planning balanced diets during various phases of life including pregnancy, lactation, infancy, childhood, adolescent, adulthood and old age have been covered. In the Unit II, key information about therapeutic nutrition i.e. principles of diet therapy, various kinds of dietary modifications in disease conditions, enteral and parenteral feeding, nutrition screening and nutrition assessment of hospitalized patients, types of diets to be planned during various diseases e.g. diseases of liver, pancreas, gall bladder, GIT, kidney, heart etc., food hypersensitivity, inherited metabolic disorders etc. has been provided in detail. In this Unit, knowledge about what kind of diet should be provided during obesity, underweight, surgery, burn condition, febrile conditions caused by infectious diseases may be due to bacteria and virus (COVID-19) has been given. A topic on nutrition for sports persons has also been covered. This book is a ready reference and an indispensable resource for students, academicians, dietitians, hospital professionals and anyone who is interested to learn about the role of human nutrition in health and disease.