Differences in Growth and Dietary and Nutrient Intake Patterns by Breastfeeding Status Over One Year Among Korean Children Aged 24-35 Months

Background: A previous national study found that Korean children who were breastfed for at least one year had lesser weight gain, lower protein, calcium, and iron intake relative to calories, and different dietary patterns in the second year of life, compared with children weaned before 12 months of age or those who were never breastfed. Therefore, this study aimed to investigate whether growth status, dietary and nutrient intake patterns differed by prolonged breastfeeding (PBF) experience even in the third year of life, when weaning is considered complete. Methods: This cross-sectional study was based on the data of children aged 24 to 35 months from the National Health and Nutrition Examination Survey (2010-2020). Data on anthropometry, dietary behavior, food and nutrient intake, maternal education, and household income were extracted to analyze the association between PBF and growth, dietary and nutrient intake patterns. Results: In the final analysis, 31.6% of the 931 children with a birth weight of >= 2.5 kg continued to breastfeed for at least 12 months of age, and their mean breastfeeding (BF) duration was 15.9 months. Children with PBF had significantly less postnatal weight gain than those without (P = 0.006). Regarding food group intake, PBF was significantly associated with lower legume and soy product intake (beta [95% confidence interval], -10.688 [-19.314, -2.062], P = 0.015) and higher fruit intake (32.978 [3.349, 62.608], P = 0.029), after adjusting for sex, age in month, total caloric intake, maternal education and household income. Regarding nutrient intake, after adjusting for these variables, PBF had significantly associated with higher dietary fiber (beta [95% CI], 1.607 [0.218, 2.996], P = 0.023), iron (0.848 [0.317, 1.380], P = 0.002) and niacin (0.728 [0.222, 1.235], P = 0.005) intake and was significantly associated with lower saturated fatty acid intake (-1.217 [-2.364, -0.071], P = 0.037) and percentage of energy from fat (-1.351 [-2.666, -0.035], P = 0.044). Conclusion: Even in the third year of life, children who have been breastfed for over one year continue to have relatively slow growth. However, they do appear to have better intake of some beneficial nutrients, which may be attributed to healthier dietary intake patterns in children with PBF. The results of this study can be used to support the recommendation of long-term BF for Korean infants and toddlers.