Development and validation of dietary assessment methods for culturally diverse populations.

Culturally diverse populations with variable dietary and disease patterns provide a unique opportunity for conducting epidemiologic studies to identify the role of diet in the etiology of chronic diseases. The dietary method for epidemiologic studies, such as cohort or case-control studies, should generally be a diet history (or quantitative food frequency) of selected food items consumed during a usual month. Knowledge of the eating patterns of each ethnic group in the study is needed to develop an appropriate questionnaire. The diet history may be validated by collecting multiple 24-h recalls or food records from representative samples of each ethnic group and comparing the mean dietary intakes with the values obtained from the diet history. Examples of studies of culturally diverse populations and the development and validation of the dietary methods are discussed.