Timing of Introduction of Complementary Foods to US Infants, National Health and Nutrition Examination Survey 2009-2014

Background Although there has been inconsistency in recommendations regarding the optimal time for introducing complementary foods, most experts agree that introduction should not occur before 4 months. Despite recommendations, studies suggest that 20% to 40% of US infants are introduced to foods at younger than 4 months. Previous studies focused on the introduction of solid foods and are not nationally representative. Objective Our aims were to provide a nationally representative estimate of the timing of introduction of complementary foods and to describe predictors of early (< 4 months) introduction. Design We conducted a cross-sectional analysis of 2009-2014 National Health and Nutrition Examination Survey data. Participants The study included 1,482 children aged 6 to 36 months. Main outcome measures Timing of first introduction to complementary foods (anything other than breast milk or formula) was analyzed. Statistical analyses performed Prevalence estimates of first introduction to complementary foods are presented by month. Logistic regression was used to assess characteristics associated with early (< 4 months) introduction. Results In this sample, 16.3% of US infants were introduced to complementary foods at < 4 months, 38.3% between 4 and < 6 months, 32.5% between 6 and < 7 months, and 12.9% at >= 7 months of age. In unadjusted analyses, early introduction varied by breastfeeding status; race/Hispanic origin; Special Supplemental Nutrition Program for Women, Infants, and Children participation; and maternal age. In adjusted analyses, only breastfeeding status remained significant; infants who never breastfed or stopped at < 4 months were more likely (odds ratio 2.27; 95% CI 1.62 to 3.18) to be introduced to complementary foods early than infants who breastfed >= 4 months. Conclusions Despite using a broader definition of complementary foods, this analysis found a lower prevalence of early introduction in this nationally representative sample than previous studies that included only solids. However, many young children were still introduced to complementary foods earlier than recommended. Strategies to support caregivers to adhere to infant feeding guidelines may be needed.