Personalized nutrition refers to the creation and delivery of dietary advice based on an individual’s unique set of intrinsic and extrinsic factors, meant to treat or prevent disease and develop eating behaviors that promote health. Thanks to the Human Genome Project as well as other historical advances in science and technology, it has become feasible to entertain the idea of truly personalized nutritional guidance. It is hoped that the implementation of such feedback will promote overall social health, and it is estimated that sometime in the near future more and more people will base food choices at least partly on their genetic, phenotypic and metabolic makeup, as well as external circumstances. This chapter seeks to provide an overview of personalized nutrition, starting at its inception and culminating with modern perspectives that delineate its importance as a possible therapeutic and preventative clinical tool in the 21st century.