As a component of a project investigating the formation of mutagens in foods under normal cooking processes, dietary practices in the U.S. were assessed for the purpose of setting priorities for food items to be tested for possible mutagen information when cooked. High-protein foods are of primary concern because cooking of these foods results in greater mutagenic activity compared to cooking of other foods. Highest priorities were given to foods on the basis of the following criteria: (a) food items high in protein, (b) food items consumed in large amounts, and (c) food items normally cooked. Some inconsistencies in the results of two national food consumption surveys were discussed, as were the problems inherent in cooking method terminology. Emphasis was given to the need for further research in cooking practices of the U.S. population.