inclusion of genetic risk factors in models of causation have made nutritional epidemiology an increasingly interdisciplinary field. Nutritional science Nutritional science is a multidisciplinary study area concerned with the role of nutrition in health and disease across the human lifespan. Nutritional epidemiology and nutritional science are two fields that share knowledge about the interactions of nutrients, food consumption, and the human body. An understanding of the principles of nutritional sciences is required to understand nutritional epidemiology. The two fields explore diet-disease relationships to provide preventative measures for the public. Research in nutritional science also provides the basis for food regulations and dietary guidelines. Knowledge from Nutritional science has raised societal awareness about links between food consumption and wellbeing. Examples of some of the successes nutritional science has contributed to findings which include linking folate deficiency to a higher risk of neural tube defects, vitamin C deficiency to scurvy, consumption of trans fat to a higher risk of cardiovascular disease and linking consumption of fish during pregnancy to reduced risk of preterm birth. These occurrences continue to be discovered with increasing scientific information and evidence, leading to more opportunities for successful intervention and prevention. Nutritional epidemiological studies Nutritional epidemiological studies form the foundation for nutrition-related discoveries. The studies reveal the relationship between nutrition and health, with a focus on aetiology of chronic disease. They provide a comprehensive view of the way in which diet affects or maintains health and wellbeing in individuals and populations. A prominent controversy lies within the ability to reliably and accurately measure exposures as they are subject to measurement errors and variation. Nutritional epidemiological study designs are required to establish a definitive relationship between diet and disease to be able to develop interventions and policies that will be implemented for the health of the public. There are observational and experimental investigations which have applicable study designs that fall under them including ecological, cross-sectional, cohort, case control, clinical and community trails. Investigators in experimental studies have the control of assigning exposures, whereas in observational studies exposures are observed only with no intervention. Experimental studies can therefore provide stronger evidence for the effect of exposure on outcome, which would otherwise be considered unethical in an observational study as exposure could be harmful. But Observational studies are simpler to carry out and more cost effective. Observational studies are able to detect rare or unusual findings over long periods of time