Precision medicine aims to improve disease treatment by tailoring it to the individual, while precision nutrition focuses on nutritional intake. Precision nutrition, often known as personalised nutrition, is concerned with the individual rather than with groups of individuals. Personalised nutrition's ultimate purpose is to maintain or improve health by using genetic, phenotypic, medical, nutritional, and other relevant information about individuals to provide more precise healthy eating guidelines and other nutritional products and services. Patients and healthy people, who may or may not have increased genetic susceptibilities to specific diseases, can both benefit from individualised nutrition. Personalised nutrition has two applications: first, for the dietary management of persons with specific conditions or who require special nutritional support—for example, during pregnancy or old age—and second, for the development of more appropriate public health interventions. Precision nutrition assumes that each person's sensitivity to specific foods and nutrients varies, therefore the optimum diet for one person may differ significantly from the best diet for another.