Use of the Revised Children's Diet Quality Index to assess preschooler's diet quality, its sociodemographic predictors, and its association with body weight status.

OBJECTIVE To determine the level of overall diet quality, sociodemographic predictors of diet quality, and the association between diet quality and body weight status in a nationally representative sample of preschoolers. METHODS Cross-sectional study using a sample of 2-5 years old with sociodemographic, dietary, and anthropometric data (n = 1,521) in the National Health and Examination Survey 1999-2002. Overall diet quality was determined using the Revised Children's Diet Quality Index. Sociodemographic predictors (age, sex, sociodemographic, ethnic group, household income, preschool attendance, federal food program participation) of diet quality were determined using multiple linear regression models in the total sample and stratified by household income for Food Stamp eligible (< 1.3 of the poverty income ratio) or Special Supplemental Program for Women, Infants, and Children eligible (poverty income ratio < 1.85). Association between diet quality and prevalence of childhood obesity was assessed with Pearson chi-square tests. Statistical significance was assumed at p <or= 0.05. All analysis was conducted using complex survey design routines. RESULTS On average, preschooler consumed suboptimal levels of whole grains, fruits, vegetables, and dairy. Overall diet quality decreased with increasing age (beta-coefficient: -2.38, p < 0.001) but improved with increasing family income in the full sample (beta-coefficient: 1.22, p < 0.001) but not in the low-income subpopulations. Mexican American children had significantly better diet quality than non-Hispanic white children (beta-coefficient: 2.18, p < 0.033) especially in the low income group (beta-coefficient: 3.57, p < 0.006). Childhood obesity prevalence decreased significantly with increasing diet quality. CONCLUSIONS Preschooler's diet quality needs to be improved to support the prevention of childhood obesity early in life.