Good health is a state of complete balance between the physical, mental and spiritual well being of a person. The science of nutrition provides us with Food as a tool to attain positive health. It educates the person about the importance and use of food nutrients to achieve and maintain good health. In this process one requires to achieve optimal development and growth in the early years of life i.e. infancy and adolescence and maintain the same structural and functional integral status of body organs throughout life so as to sail through ageing with minimal discomfort and to develop immunity to resist infections, diseases etc. This can be done by calculating the nutrient needs of a particular individual at a particular stage in life and prescribing a dietary intake regime that fulfills the present demand of nutrients as well as creates a small reservoir to provide for any future requirement.