Differences in Infant Diet Quality Index by Race and Ethnicity Predict Differences in Later Diet Quality

Racial and ethnic disparities in infant-feeding practices may negatively influence diet quality and health.

This study investigated the racial, ethnic, and language (English or Spanish) differences in infant diet quality, later diet quality, and weight status at 2-5 y, and whether these differences were explained through infant diet quality among participants in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC).

Using the WIC Infant and Toddler Feeding Practices Study-2 (unweighted n = 2663; weighted n = 362,712), relationships between the Infant Dietary Quality Index (IDQI; range 0-1) and Healthy Eating Index-2020 (HEI-2020; range 0-100) and BMI z-score (BMIz) at 2-5 y were analyzed by race, ethnicity, and language preference [Hispanic Spanish-speaking, Hispanic English-speaking, non-Hispanic (NH) White, and NH Black participants]. Statistical interaction between IDQI and each group was evaluated in multivariable models. The mediation of each group through the IDQI was assessed using causal mediation methods.

Differences in IDQI [mean (standard deviation)] were observed between Hispanic Spanish-speaking participants [0.41 (0.10)], Hispanic English-speaking participants [0.37 (0.10)], NH White participants [0.36 (0.10)], and NH Black participants [0.35 (0.09)], P < 0.001. Differences in HEI-2020 occurred at 2-5 y, with the Hispanic Spanish-speaking participants having consistently higher HEI-2020 scores. Differences in BMIz were observed at 5 y, with higher scores among Hispanic Spanish-speaking participants. Interaction between race, ethnicity, and IDQI was observed for all outcomes except for BMIz at 3 y. Through mediation, IDQI explained 13%-20% of the difference in HEI-2020 scores between Hispanic Spanish-speaking and NH White participants at 2-5 y. IDQI explained 22%-25% of the difference in HEI-2020 scores between the Hispanic Spanish-speaking and NH Black participants at 4 y and 5 y.

Higher infant diet quality scores observed in Hispanic Spanish-speaking participants explain some of the racial and ethnic differences observed in later diet quality, suggesting that improving infant diet quality may help reduce diet disparities during early childhood.