23rd Lenna Frances Cooper memorial lecture: a diet history method for research, clinical, and community use.

A structured quantitative diet history method has been developed and utilized in several cancer epidemiological studies in Hawaii. The objective was to design a questionnaire that would yield a valid and reproducible assessment of the usual frequency and quantity of food and nutrient intakes by individuals and that could be administered by trained lay interviewers. The questionnaire consists of a list of food items selected to provide an estimate of 85% or more of the intakes of particular nutrients during a usual week or month. Amounts consumed are estimated from photographs showing each item in three serving sizes. The procedures used in developing the diet history questionnaire are described. Briefly, the steps include: collection of frequency and quantitative data on foods consumed (food records) by a sample of the population, interpretation and coding of the food records, selection of food items for the questionnaire, identification of appropriate serving sizes of the selected food items, selection of a visible technique for showing different portion sizes to the subjects, establishing the reference period for the diet history, and training of the interviewers. The use of the method in various epidemiological studies, current research on dietary methodology, and applications of the method for clinical and community use are discussed.