How much breast milk do babies need?

A reassessment of the breast milk requirements of young babies at different ages has been made from a statistical analysis of energy intake data collected prospectively in Cambridge, U.K. and from data derived from a literature survey of cross-sectional food energy intakes of infants from Canada, Sweden, the U.K. and USA. In contrast to the slow progressive linear decline in energy requirements per kg body-weight that has previously been assumed, measured intakes have been shown to fall more rapidly in the first six months of life. Thereafter they then rise again as the baby becomes more active. These findings are of fundamental importance to a realistic assessment of the adequacy of breast milk as the sole source of food in the first six months of life. The data show that typical breast milk intakes found in the industrialized countries can satisfy infant energy needs for healthy growth for much longer than would be indicated by current international dietary recommendations. A discussion of the physiological interpretation of the results is included as is an appraisal of their practical significance both to breast and bottle feeding practices.