A connection between food and health has been known to exist since the dawn of history. However, the advent of modern science refined this concept to an understanding that our health depends upon obtaining certain nutrients in specific quantities. This heralded the concept that improper nutrition may directly lead to disease states and spawned dozens of professions and fields of research that focus on the relationship between nutrition and health. This in turn has led to an exponential growth in our understanding of human nutrition and to the creation of dietary recommendations such as the Institute of Medicine’s Dietary Reference Intakes (DRI’s). Recently, advances in genetic technologies such as the sequencing of the human genome have begun to revolutionize the field of nutrition and radically altering the direction of research. Hundreds of genetic variants that predispose individuals to common diseases have been identified and as research continues the number of known disease-predisposing polymorphisms will multiply. However, human health does not solely depend on our genes but also on our environment. Understanding how these two factors interact is paramount to disease prevention and our diet has been identified as one of the most important factors to interact with our genes. Hence thecreation of a new field within nutrition, nutrigenetics. Nutrigenetics aims to understand how the genetic makeup of an individual coordinates their response to diet. Therefore, nutrigenetics considers the genetic polymorphisms of an individual and how these variations interact with disease risk and diet. As research progresses, nutrigenetics will produce information that will assist clinicians in identifying the optimal diet for a given individual, i.e., personalized nutrition. If these goals are to be realized the field of nutrition must move beyond epidemiological studies using genetically uncharacterized populations and incorporate more complex models that account for cellular and molecular biology coupled with biochemistry and genetics. The burgeoning field of nutrigenetics has already discovered dozens of “candidate gene variants” which may confer a heightened sensitivity to specific nutritional factors and are known to modulate disease risk. Some of these genes have functionally important variations that are highly prevalent in the population. Genetic variation within these genes may explain discrepancies in previous epidemiologic studies that sought to find inte...