Nutritional sciences are the study of food, nutrients, and other food substances, as well as how they are taken in and processed biochemically, how they affect health and disease, and how this information can be used to make policies and programs. It has a wide variety of potential uses. Nutritionists study the consequences of nutritional deficits and excesses for illness prevention and treatment, and they have a thorough grasp of how food is digested, absorbed, and metabolized at various points in the lifespan. As in this book, professionals who work in the area of nutritional science also rely on their understanding of the social sciences to comprehend the socio-cultural, psychological, economic, and political aspects impacting food choices and health standards. Focuses on nutrition range from the investigation of biochemical pathways and their connections with genetics (nutritional genomics) to the observation of dietary intake and its association with health outcomes (nutritional epidemiology) to the development and evaluation of treatments intended to boost community health to the administration of policies and programs meant to increase people’s access to healthy foods.