**4. Nutritional genomics**

Nutrigenetics and nutrigenomics are promising multidisciplinary fields that focus on studying the interactions between nutritional factors, genetic factors and health outcomes. Their goal is to achieve more efficient individual dietary intervention strategies aimed at preventing disease, improving quality of life and achieving healthy aging (Ordovas., 2004).

In contrast to most single gene disorders, chronic disorders (e. g., cardiovascular disease, cancer, diabetes) are far more complex. First, they involve multiple genes, each of which comes in more than one variation, that likely contribute in small ways to the overall condition rather than have the dramatic impact that is more typical with single gene disorders. Second, the genes are more likely to be influenced by environmental factors, which make the resulting phenotype murkier than with single-gene disorders. An individual might have gene variants that predispose to a particular chronic disorder but, depending on that individual's nutritional and other lifestyle choices, the disorder may or may not develop (DeBusk., 2008).

Nutritional genomics or nutrigenomics is the newly developing field of science that focuses on the complex interaction among genes and environmental factors, specifically bioactive components in food and how a person's diet interacts with his or her genotype to influence the balance between health and disease (DeBusk., 2009; Much et al., 2005; Fisler & Warden., 2005).

Nutritional genomics is the umbrella term (Ryan-Harshman., 2008). There are two major subcategories of nutritional genomics: nutrigenetics and nutrigenomics (Much et al., 2005).

The creation of nutrigenomics and nutrigenetics, two fields with distinct approaches to elucidate the interaction between diet and genes but with a common ultimate goal to optimize health through the personalization of diet, provide powerful approaches to unravel the complex relationship between nutritional molecules, genetic polymorphisms, and the biological system as a whole (Much et al., 2005).

Thus, nutrition in the 21st century is poised to be an exciting and highly relevant field of research, as each new day is accompanied by advances in our understanding of how the interactions between lifestyle and genotype contribute to health and disease, taking us one step closer to achieving the highly desirable goal of personalized nutrition (Much et al., 2005)**.** 
