School Nutrition Dietary Assessment Study: overview of the study design.

The School Nutrition Dietary Assessment Study collected information from a nationally representative sample of schools and a nationally representative sample of students attending these schools. A total of 545 schools provided information about all meals served during a 1-wk period between February and May 1992, as well as information about school food service operations. Approximately 3350 students in grades 1-12 provided detailed information about the foods and beverages that they consumed during a 24-hr period that included a school day. To assess the content of both the school meals offered to students and the meals consumed by students, the study used dietary standards from three sources: the recommended dietary allowances, the Dietary Guidelines for Americans, and recommendations of the National Research Council.