title: GI Epidemiology: nutritional epidemiology.
abstract: BACKGROUND
  Nutritional epidemiology is the assessment of diet and its relationship to disease aetiology in populations. The choice of dietary assessment method depends on the disease pathology. Events such as cancer that are chronic and complicated by exposure time require methods that capture consumption patterns of populations over a period of years. Although several methods of dietary assessment exist for collecting information on groups of individuals, their application to epidemiologic studies requires an understanding of the effect of variability in nutrient intake, sources of measurement error, and statistical issues unique to the study of nutritional epidemiology.
  
  
  OBJECTIVE
  This review provides an overview of commonly-used methods of dietary assessments in epidemiologic studies, and identifies their strengths and limitations and application to epidemiologic study designs. It concludes with a brief discussion of assumptions of nutrient databases and objectives of energy-adjustment and measurement error correction models.
  
  
  CONCLUSIONS
  Nutritional epidemiology has contributed significantly to our understanding of the relationships between diet and disease. Ongoing investigations that further characterize important exposure periods (early life, in utero) and clarify associations within the context of genetic susceptibility will continue to elucidate our understanding of the pathophysiology of complex diseases, and support future recommendations for disease prevention.
authors.forename: L E
authors.initials: LE
authors.lastname: Kelemen
mesh_terms: D000328:Adult; D000368:Aged; D004032:Diet; D004194:Disease / Q000209:etiology*; D004812:Epidemiologic Methods; D004813:Epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D012307:Risk Factors