Specific infant feeding practices do not consistently explain variation in anthropometry at age 1 year in urban United States, Mexico, and China cohorts

Infant feeding practices generally influence infant growth, but it is unclear how introduction of specific foods affects growth across global populations. We studied 3 urban populations in the Global Exploration of Human Milk study to determine the association between infant feeding and anthropometry at 1 y of age. Three hundred sixty-five breastfeeding mother-infant pairs (120 US, 120 China, and 125 Mexico) were recruited soon after the infant’s birth. Enrollment required agreement to breastfeed ≥75% for at least 3 mo. Weekly, 24-h, food frequency data were conducted on infants for 1 y and exclusive breastfeeding (EBF) duration and timing of specific complementary food introduction were calculated. Weight and length were measured at age 1 y and anthropometry Z-scores calculated using WHO standards. Cohorts in the 3 urban populations (Shanghai, China; Cincinnati, USA; and Mexico City, Mexico) differed by median EBF duration (5, 14, and 7 wk, respectively; P < 0.001), timing of introduction of meat/eggs/legumes (4.8, 9.3, and 7.0 mo, respectively; P < 0.0001), and other feeding practices. By age 1 y, infants in Shanghai were heavier and longer than Cincinnati and Mexico City infants (P < 0.001). Adjusting for nonfeeding covariates, the only feeding variable associated with anthropometry was EBF duration, which was modestly inversely associated with weight-for-age but not length-for-age or BMI Z-scores at 1 y. Although feeding variables differed by cohort, their impact on anthropometry differences was not consistent among cohorts. Overall, across these urban, international, breast-fed cohorts, differences in specific feeding practices did not explain the significant variation in anthropometry.