Identifying a limited number of foods important in supplying selected dietary nutrients.

Three methods were developed to identify a limited number of foods that are important dietary contributors of fat, dietary fiber, and vitamins A, C, and E. In the first method, foods were ranked by the amount of each nutrient supplied per person per day and the effect each food had on the relative ranking of individuals with respect to the intake of those nutrients. Foods scoring high on both scales for a given nutrient were selected as important dietary contributors of that nutrient. In the second method, foods were selected according to the mean nutrient contribution per consumer (nonconsumers of a food were eliminated from this estimation procedure). In the third method, foods were selected that contributed a relatively large percentage of the total dietary intake of a given nutrient. The three methods were applied to data from an extensive dietary questionnaire. The authors then compared the limited lists of foods identified by each method. Generally, the methods yielded similar food lists. Regression analysis was then employed to test the ability of the selected foods to predict the nutrient totals calculated from the original, more extensive dietary questionnaire. The results suggest that a limited number of foods may have strong predictive ability, but that has not been tested in any other population.