ABSTRACT
Nutritional epidemiology is defined as the study of the nutritional determinants of disease in human populations (Langseth 1996). The function of nutritional epidemiology is to identify and study associations between diet and disease in defined populations. Although it originally focused on nutrient deficiency diseases, contemporary nutritional epidemiology greatly concerns the study of heart disease, cancer, diabetes, osteoporosis, and neural tube defects (NTDs). These irreversible chronic conditions have multiple causes and long latency periods, occur with relatively low frequency (despite a substantial cumulative lifetime risk), and are associated with excessive as well as insufficient intake of nutrients and other food factors (Willett 1998a). A major enterprise of nutritional epidemiology is to assess the efficacy of nutrition interventions-including nutrition education, policies, and programs-and to develop diet assessment methods that enable public health officials and researchers to monitor dietary intake and other health-related behaviors of defined populations. Epidemiological methods are widely applied in public health nutrition, and even practitioners who do not carry out surveys themselves will find that their public health practice is influenced by epidemiological observations.
