Measures of overall diet quality from a food frequency questionnaire: National Health Interview Survey, 1992

We developed dietary variety based measures of diet quality using food frequency questionnaire (FFQ) data from the National Health Interview Survey (NHIS), 1992. FFQs from 10,799, aged greater than or equal to 18 years, were examined. We grouped the 68 items in the NHIS FFQ into two categories-nutrient-dense, and energy-dense, nutrient-poor. A dietary variety score (DVS), comprised of the number of food items mentioned at least once a week from the nutrient-dense group (54 items), was calculated for each respondent. A dietary variety score for recommended (DVSR) foods was also computed. The DVSR counted at least weekly mentions of foods recommended in current dietary guidance (27 items). The mean+/-SE of DVS and DVSR were 21+/-0.1 and 11.6+/-0.1, respectively. Education, total energy, calcium, vitamin C, carotenoid intakes, and compliance with recommendation of the Food Guide Pyramid correlated positively with the DVS and DVSR. Percent energy from fat was inversely related with DVSR, but was unrelated with DVS. Nutrition knowledge correlated positively with both scores. In conclusion, the scores developed were correlated with nutrient and food group intake, and may be suitable for assessment of these attributes of diet quality when only limited dietary information is available. (C) 1997 Elsevier Science Inc.