Lactational capacity of marginally nourished mothers: infants' milk nutrient consumption and patterns of growth.

The consumption of human milk by 58 Bangladeshi infants of marginally nourished mothers was measured during longitudinal studies. Daily milk consumption, as estimated by test weighing, and intakes of energy and protein, as calculated from the measured concentrations of macronutrients in the milk, were related to infant body weight, to internationally recommended intakes of these nutrients, and to the infants' patterns of physical growth. Each of the milk variables, when related to infant body weight, declined significantly with increasing (log) infant age (P less than .001). The average consumption of energy and protein was less than current recommendations at all ages. Nevertheless, the average growth of the Bangladeshi infants approximated the fifth centile of the US National Center for Health Statistics during the first 4 months of life. By the fourth month, however, the weight increments of more than half the infants (79%) were less than the reference data. The intakes of energy and protein by individual infants less than 90 days of age were related to their patterns of growth. There were significant positive relationships between the change in Z score weight-for-age and weight-for-length and the consumption of breast milk energy (kilocalories per kilogram of body weight per day) and protein (grams per kilogram per day). Consumptions of 86.5 kcal/kg/d and protein 1.48 g/kg/d were associated with a nonchanging Z score weight-for-age. Thus, intake of these amounts of nutrients permitted weight gain comparable to the reference population but did not permit recovery from the existing relative weight deficits.