Validity and reliability of a modified qualitative dietary fat index in low-income, overweight, African American adolescent girls

This study evaluated the validity and reliability of a modified qualitative dietary fat index questionnaire (QFQ) in an adolescent minority population. The QFQ was administered to study participants twice over a 2-week period, and data were compared with mean values from three 24-hour recalls. Fifty-seven low-income, overweight, African American adolescent girls, aged 11 to 17 years, were recruited from 7 public housing developments in Atlanta, Georgia. To determine validity, the total QFQ score was compared with the mean values of total fat, percentage of energy from fat, and total energy from three 24-hour recalls within 2 weeks of first administration of the QFQ. Reliability was tested in a subsample (n=22) by comparing total QFQ scores administered 2 weeks apart. Total fat was significantly correlated (r=0.31, P<.05) with the QFQ score. Total energy (r=20.23) and percentage of energy from fat (r= -0.23) were not significantly correlated with the QFQ score. The test-retest QFQ scores were significantly correlated (r=0.54, P<.01). The data suggest that additional modifications are needed to make the QFQ more appropriate for low-income, overweight, African American adolescent girls.