Validation of a new scoring approach of a child dietary questionnaire for use in early childhood among low-income, Latino populations.

Background: Measuring diet quality in early childhood requires time-intensive and costly measurements (e.g., 24-hour diet recall) that are especially burdensome for low-income, minority populations. This study aimed to validate a new method for calculating overall diet quality among low-income, Latino preschoolers.

Methods: This study was an observational study using data from a randomized controlled trial. Participants included parents of Latino preschoolers who reported child diet quality at baseline, 4-month, 7-month, 12-month, and 13-month follow-up. At each timepoint parents responded to a 28-item child dietary questionnaire (CDQ), based on the National Health and Nutrition Examination Survey (NHANES) dietary module, which generated the number of times/day that a child ate each of 28 foods in the past month. These 28 items were then used to create a total standardized child diet quality index (possible range 0-100), using a percent of maximum method. Parents were asked to complete three 24-hour diet recalls at the 13-month follow-up, from which the 2015 Healthy Eating Index (HEI) was derived. Construct validity was evaluated by Spearman's rank correlations between the new child diet quality index and the 2015 HEI at the 13-month follow-up. Test-retest reliability was assessed by intraclass correlation coefficients (ICC) for sequential pairs of time points.

Results: Among 71 eligible parent-child pairs, mean child age was 4.2 (SD = 0.8) years, 50.7% of children were female, and mean child body mass index (BMI) was 17.8 (SD = 2.0) kg/m. Mean Child Diet Quality Index was 45.2 (SD = 3.2) and mean HEI was 68.4 (SD = 10.5). Child Diet Quality Index and HEI total scores were significantly correlated (r = 0.37; p = 0.001). Test-retest ICCs were statistically significant between all sequential pairs of time points.

Conclusion: The new approach for calculating a measure of overall diet quality from the previously-validated 28-item dietary questionnaire demonstrated modest construct validity. When time and resources are limited, this new measure of overall diet quality may be an appropriate choice among low-income, Latino preschoolers.

Trial Registration: This reports presents observational data collected as a part of a clinical trial, which was registered on clinicaltrials.gov prior to participant enrollment (NCT03141151).