ABSTRACT
Introduction ............................................................................................................................................................................. 493 Methods of Dietary Assessment .............................................................................................................................................. 494
Food Records ..................................................................................................................................................................... 494 Recalls ................................................................................................................................................................................ 495 Food Frequency Methods ................................................................................................................................................... 496 Summary ............................................................................................................................................................................ 497
Issues Affecting Validity ......................................................................................................................................................... 497 Memory .............................................................................................................................................................................. 498 Portion Sizes....................................................................................................................................................................... 498 Consumption Frequency .................................................................................................................................................... 499 Response Bias .................................................................................................................................................................... 499 Variability of Intake ............................................................................................................................................................ 499 Data Entry .......................................................................................................................................................................... 500 Summary ............................................................................................................................................................................ 500
Current Issues in Assessment and Analysis ............................................................................................................................ 500 Reporting Accuracy ........................................................................................................................................................... 500 Diet Quality ........................................................................................................................................................................ 501
Indexes ........................................................................................................................................................................... 501 Energy Density .............................................................................................................................................................. 501 Glycemic Index/Glycemic Load ................................................................................................................................... 502
Dietary Supplements .......................................................................................................................................................... 502 Functional Foods ................................................................................................................................................................ 503
References ............................................................................................................................................................................... 503
There has been long-standing interest in assessing diets of individuals. Early in the twentieth century, nutritionists studied food and nutrient intakes in order to provide guidance in food selection,2 to interpret clinical and laboratory ndings,3 and to establish dietary requirements.4 In the latter part of the century, interest in dietary assessment was stimulated with the increasing evidence for the role of diet in promoting health and reducing chronic disease risk.1,5
Early investigators were concerned with many of the issues that continue to be important for dietary assessment: (1) selecting appropriate methods for collecting dietary data,6,7 (2) assessing the day-to-day variability of intakes by individuals,8-10 (3) establishing procedures for data analysis,11,12 and (4) estimating food/food group and nutrient intake.3
