Measuring dietary exposure in nutritional epidemiological studies.

C O N T E N T S I N T R O D U C T I O N . E P I D E M I O L O G I C A L P R I N C I P L E S RELEVANT T O D I E T A R Y S T U D I E S . D E F I N I N G EXPOSURE A N D O U T C O M E . G E N E R A L ISSUES T O BE C O N S I D E R E D W H E N ASSESSING D I E T A R Y E X P O S U R E S . COMPLEXITY OF DIETARY EXPOSURE. D 0 SE-R E S P 0 N S E RE L A T I 0 N S H I P . PH Y SI OLOG I c A L/M ETA BOL I c R EQU I REMEN TS . MULTIPLE F U N C T I O N S . INTERACTION . BIOAVAILABILITY . BIOEQUIVALENCE . . C R I T I C A L TIME PERIODS . BIOLOGICAL MARKERS . . THE RELEVANT EXPOSURE . E P I D E M I O L O G I C A L APPROACHES T O M E A S U R I N G EX P 0 S U R E-0 U T C 0 M E R E L A T I 0 N S H I PS . SUMMARY OF OBSERVATIONAL I N D I V I D U A L BASED STUDY DESIGNS . Cohort studies . Case-control studies . Cross-sectional studies . D I E T A R Y MEASURES I N E P I D E M I O L O G I C A L S T U D I E S . . EXPERIMENTAL STUDIES . COHORT STUDIES . CASE-CONTROL STUDIES . CROSS-SECTIONAL STUDIES . V A L I D I T Y . CALIBRATION OF MEASURES. . REPEATABILITY . EXAMPLES O F QUESTIONS A N D APPROACHES W H I C H MAY BE