The growth of breast fed and artificially fed infants from birth to twelve months.

Growth data collected from 394 healthy infants were analysed in relation to feeding practices. Infants were grouped on the basis of sex, if breast fed or artificially fed, and duration of breast feeding. From birth to 3 months, weight gains were similar for boys (2.5 kg) and also for girls (2.3 kg) irrespective of feeding method. From 3 to 6 months weight gains were greater in infants who were artificially fed from birth (2.0 kg both sexes) or breast fed for only a short time (1.9 kg) than for those exclusively breast fed for 6 months (1.6 kg) or longer (1.7 kg). Weight gains continued to be greater in artificially fed infants after 6 months. Over 12 months, artificially fed boys gained 410 g and girls 750 g more than those who were breast fed from birth. These differences occurred even though the artificial feedings that prevailed to 6 months and longer were low-solute ('humanized') formulas.