Assessing nutrient intake with an abbreviated dietary interview.

There is considerable interest in developing a means of assessing dietary intake of specific nutrients with minimal time and expense in epidemiologic studies. Using data from 1,682 individuals who were interviewed using an extensive food frequency dietary history, the authors examined the question of how many foods might be minimally required in order to estimate specific nutrient intakes for epidemiologic purposes. Nutrient indices were constructed for vitamins A and C, dietary fiber, fat, protein, and total calories based on 128 foods included in the interview. They found that a large fraction of the variability of nutrient intake in this population could be explained by a small number of foods. An abbreviated dietary history ascertaining the intake of as few as 15-20 food items may be all that is required in order to test the association between disease outcome and the intake of a single nutrient.