The role of infant feeding practices in the explanation for ethnic differences in infant growth: the Amsterdam Born Children and their Development study

Rapid early growth in infants may influence overweight and CVD in later life. Both rapid growth and these disease outcomes disproportionately affect some ethnic minorities. We determined ethnic differences in growth rate (Δ standard deviation scores, ΔSDS) during the first 6 months of life and assessed the explanatory role of infant feeding. Data were derived from a multiethnic cohort for the Amsterdam Born Children and their Development study (The Netherlands). Growth data (weight and length) of 2998 term-born singleton infants with no fetal growth restriction were available for five ethnic populations: Dutch (n 1619), African descent (n 174), Turkish (n 167), Moroccan (n 232) and other non-Dutch (n 806). ΔSDS for weight, length and weight-for-length between 4 weeks and 6 months were defined using internal references. Infant feeding pattern (breast-feeding duration, introduction of formula feeding and complementary feeding) in relation to ethnic differences in growth rate was examined by multivariate linear regression. Results showed that the growth rate was higher in almost all ethnic minorities, with β between 0·07 and 0·41 for ΔSDS weight and between 0·12 and 0·42 for ΔSDS length, compared with ethnic Dutch infants. ΔSDS weight-for-length was similar across groups, except for Moroccan infants (β 0·25, P < 0·05) after correction for confounders. In general, exclusive breast-feeding for 4 months was associated with slower growth for all three growth measures. Feeding factors explained, to a small degree, the higher weight and length gain in African descent infants, but not the higher ΔSDS weight-for-length in the Moroccan population. More research is needed to elucidate the underlying mechanisms of the high infant growth rate in Turkish and Moroccan infants.