Breast milk or animal-product foods improve linear growth of Peruvian toddlers consuming marginal diets

Abstract
Although breast-feeding is widely accepted as important for infant health, its benefits during the second year of life have been questioned. We analyzed data from 107 breast-fed and weaned Peruvian children living in a periurban community to determine whether breast milk contributed to improved linear growth between 12 and 15 mo of age. Breast-feeding frequency was self-reported; intakes of complementary foods and animal products were estimated from a food-frequency survey. Multivariate-linear-regression analysis was used to predict the length of the children at 15 mo of age. Determinants of length included length and weight-for-length at 12 mo of age (US National Center for Health Statistics standards), interval between 12- and 15-mo measurements, breast-feeding frequency, incidence of diarrhea, and intakes of complementary and animal-product foods. Complementary foods, animal-product foods, and breast milk all promoted toddlers’ linear growth. In subjects with low intakes of animal-product foods, breast-feeding was positively associated (P < 0.05) with linear growth. There was a 0.5-cm/3 mo difference in linear growth between weaned toddlers and children who consumed the average number of feedings of breast milk. Linear growth was also positively associated with intake of animal-product foods in children with low intakes of complementary foods. The negative association between diarrhea and linear growth did not occur in subjects with high complementary-food intakes. When the family’s diet is low in quality, breast milk is an especially important source of energy, protein, and accompanying micronutrients in young children. Thus, continued breast-feeding after 1 y of age, in conjunction with feeding of complementary foods, should be encouraged in toddlers living in poor circumstances. The contribution of prolonged breast feeding to linear growth at 12-15 months of age was investigated in 107 breast-fed and weaned toddlers from a low-income neighborhood in Lima, Peru. The median duration of breast feeding in this sample was 17.1 months; by 15 months, 46 children had been weaned. The prevalence of stunting (length-for-age score -2 SD below the reference standard) was 17.8% at 12 months and 24.3% at 15 months; no child was wasted. Complementary foods, animal product foods, and breast milk all promoted toddlers’ linear growth. In children with low intakes of animal product foods, breast feeding was positively associated with linear growth at 15 months (p 0.05). There was a 0.5 cm/3 months difference in linear growth between weaned toddlers and those who consumed the average number (6.3/day) of breast feeds. Linear growth was further positively associated with intake of animal product foods in children with low intakes of complementary foods. The negative association between diarrhea and linear growth did not occur in children with high intakes of complementary foods. When the household diet is of poor quality, breast feeding is an especially important source of energy, protein, and micronutrients in toddlers and should be continued beyond 12 months of age in conjunction with the provision of complementary foods. Breast milk not only added to the total diet of these young children, but also potentiated the beneficial effects of complementary foods consumed by increasing their growth promotion capacity.