Total diet studies: the identification of core foods in the United States food supply.

Some total diet studies are based on the selection and analysis of core foods in a national or regional food supply. One way to select core foods is by computerized evaluation of the daily food intakes reported by subjects participating in national food consumption surveys. The foods consumed by the population groups of concern may be aggregated into core food groups. The foods within each group may be ranked according to daily intake and weight percentage of the total diet. The food that best represents each group may then be identified as a core food, and the daily consumption levels for each food group may then be assigned to the core food representing the group. Consumption levels may be determined for the specific age-sex categories of concern. To assess the representativeness of core foods identified in this manner, the food composition database of the national survey may be used to determine nutrient intakes based on the full range of foods in the database versus nutrient intakes based on the core foods.