Nutrition is the process by which living things use food to obtain nutrients for energy, growth and development as well as maintenance. Nutrients are biochemical substance that can be supplied only in adequate amounts from an outside source, normally from food. Nutrition is relatively a new science, still an evolving process. Psychological factors such as preference for taste and social factors such as habit, ethnic heritage, tradition and values that enter into frequent decisions concerning food choices are important aspects of nutrition. As a body of knowledge, dietetics and nutrition has expanded to impact many segments of health care. Oral health and nutrition have a synergistic bidirectional relationship. Scientific and epidemiological data show a lifelong synergy between nutrition and the integrity of oral cavity in health and disease.