Development and validation of a semi-quantitative food frequency questionnaire for young adult women in the southwestern United States

The purpose of the study was to develop and validate a multicultural food frequency questionnaire (FFQ) for young women in the southwestern United States. The instrument was validated against 3-day diet records in 95 college women, and cross-validated against the mean of two 24-hour recalls and 4-day food records in 50 low-income postpartal women. Internal consistency reliability was assessed via Cronbach's alpha. Validity was examined via descriptive statistics, Pearson's correlations, and cross-classification by quartile categories. Cronbach's alpha averaged 0.75 for food groups in college women and 0.73 in low-income women. De-attenuated Pearson's correlations centered at 0.42 among college women and at 0.45 among low-income women. Cross-classification of participants into quartiles of nutrient intake resulted in 76% of college women and 79% of low-income women being classified correctly. These results suggest that the FFQ is reliable and valid for dietary assessment among young women in the southwestern United States.