Validity of 24-hour dietary recalls by adolescent females.

The validity of 24-hour dietary recalls was tested by comparing the recalled intake of adolescent girls to their actual intake during a metabolic study. Diet recalls were a valid bases of estimating the dietary intake of energy, protein, calcium, and zinc by this group of adolescents. However, the majority of the subjects were unable to recall their food intake with enough accuracy so that their intake of vitamins A and C, thiamin, riboflavin, niacin, and iron could be calculated within the range of two-thirds to four-thirds of their actual intake.