Future of dietary exposure assessment.

Nutritional epidemiology depends on valid assessment of exposure of individuals to food-borne factors. The tools being applied are generally blunt instruments that are simple for the scientist to administer and analyze. The burden of aggregating foods, combining amounts, drawing on episodic or generic memory, and interpreting the questions is placed on the subjects. Alternative approaches include enhanced use of biomarkers of exposure as external, internal, and target tissue markers. Because biomarkers exist for only a few substances of interest at the exposure time of interest, the future of subjective measures is likely to be in the development of subjective dietary assessment methods that apply modern technology, including audio systems to overcome literacy barriers and allow multilingual interviews, and pictures for identifying foods. Automated methods can ensure that all questions have been responded to and all responses outside of normal ranges have been double-checked. Computer-assisted self-interviewing (CASI) may prove to be the most economic and cognitively supportive approach for assessment of food-borne exposures in the future.