Dietary intake and nutritional status.

Though dietary factors are implicated in chronic disease risk, assessment of dietary intake has limitations, including problems with recall of complex food intake patterns over a long period of time. Diet and nutrient biomarkers may provide objective measures of dietary intake and nutritional status, as well as an integrated measure of intake, absorption and metabolism. Thus, the search for an unbiased biomarker of dietary intake and nutritional status is an important aspect of nutritional epidemiology. This chapter reviews types of biomarkers related to dietary intake and nutritional status, such as exposure biomarkers of diet and nutritional status, intermediate endpoints, and susceptibility. Novel biomarkers, such as biomarkers of physical fitness, oxidative DNA damage and tissue concentrations are also discussed.