Human milk intake and growth faltering of rural Mesoamerindian infants.

To determine whether growth faltering during early infancy was attributable to inadequate intake of human milk, the nutrient intakes and growth of 30 Otomi infants from Capulhuac, Mexico, were studied at 4 or 6 mo of age. Growth was monitored monthly from 1 through 6 mo of age. The 2H dose-to-the-mother method was used to measure human milk intake. Energy, protein, lactose, and fat concentrations in milk were analyzed by standard techniques. Mean (+/- SD) human milk intakes were 885 +/- 145 and 869 +/- 150 g/d at 4 and 6 mo, respectively. Protein and lactose concentrations in milk were normal but fat and consequently energy concentrations were abnormally low. Energy intakes averaged 81 +/- 14 kcal.kg-1.d-1 at 4 mo and 72 +/- 14 kcal.kg-1.d-1 at 6 mo. Growth faltering by 6 mo was evidenced by the significant decline in growth velocities and National Center for Health Statistics Z scores. Weight gain at 6 mo was 8.1 +/- 3.5 g/d and length gain was 1.0 +/- 0.34 cm/mo. Weight-for-age and length-for-age Z scores were -0.81 +/- 0.94 and -1.51 +/- 0.83, respectively. Growth velocities were not significantly correlated with nutrient intakes. Growth faltering among the Otomi infants despite energy intakes comparable to those of breast-fed infants in more protected environments may have resulted from an increase in the need for nutrients or from a growth-limiting nutrient, other than energy, in their diet.