Food and nutrients provide the energy and building materials for the all the substances that are essential to the growth and survival of living things. In simplest way, nutrition is the study of how food nourishes the body. This course module provides an integrated overview of the physiological requirements and functions of protein, energy, and the major vitamins and minerals that are determinants of health and disease. Having a good understanding of the principles of nutrition is particularly important because there is now overwhelming evidence that not only malnutrition but also the incidence of the diseases of our present day society – heart disease, hypertension, cancer, osteoporosis, obesity, among others – can be influenced by diet. Topics of this course include dietary sources, intake levels, and biological determinants of nutrient requirements and deficiency and excess conditions of micro and macronutrients.