Poor Validity of Dietary Recall in Low-Income Hispanic Children using Digital Food Imaging Analysis as the Reference

Background: The prevalence of obesity among all U.S. children continues to increase but among Hispanic children the increase is more pronounced. With childhood obesity and technology on the rise, conventional methods of assessing dietary intake through memory recall might need to be complemented with newer technologies. Objective: To test the sensitivity and specificity of self-reported dietary recall using Digital Food Imaging Analysis as the reference. Design: The study was observational where a cohort of students was followed prospectively for three consecutive days. Participants: Third and fourth grade students ages eight to nine years from six elementary schools of two school districts (n = 213) of which most were Hispanic and economically disadvantaged. Main outcome measures: Three day, 24 hour dietary recalls were collected during three consecutive days of meals they consumed the day before. On the same day of the analysis two stationary Internet Protocol cameras were taking images of preand post-meals. In this study only school breakfast and lunch meals were analyzed. Statistical analyses performed: This study used a 2 × 2 contingency table to analyze the dietary recall for specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV). Sensitivity = TP/(TP +FN), Specificity = TN/(TN + FP), PPV = TP/(TP + FP), and NPV = TN/(TN + FN); where TP = true positive, TN = true negative, FP = false positive, and FN = false negative. These then were tested for mean, standard deviation and 95% confidence. Results: The sensitivity, specificity, PPV and NPV for the three days of dietary recall were 56%, 35%, 64%, and 27% respectively. Conclusions: This study showed that self-reported dietary recalls were inaccurate assessing dietary intake in Hispanic children, ages eight to nine years, living in economically disadvantaged households. Methods using new technologies such as digital photography to complement memory recall should be explored.