Overfeeding in infancy

Several studies have drawn attention to the potential dangers inherent in the excessive intake of energy and solute loading in newborn and young infants It is only comparatively recently that these problems have become manifest (British Medical Journal, 1973), partly because the doctrine that 'one cannot overfeed a young infant' has died hard, and partly because they are the consequences of the increasing use of full-cream cow's milk formulas for the artificial feeding of infants, supplemented, at an early age, with solid material. It is important to recognize that it is not merely a question of excessive intakes of energy and solutes as such. The detailed character of the solute and its composition is equally important, as is the effect of such changes on the water intake, and therefore the external water balance of the infant. Our own interest in this topic was first aroused by the observation of a very high incidence in this country of hypernatraemic dehydration in children with gastroenteritis. The reported incidence (Ironside, Tuxford & Heyworth, 1970) of this complication (63%) is three times higher than that quoted in the American literature It occurred to us that this might be in some way bound up with the tendency for babies in this country to be given milk formulas composed of full-cream cow's milk, as opposed to the United States where either evaporated full-cream cow's milk is used, or, alternatively, relatively lowsolute feeds resembling breast-milk are given. We were also interested in the apparently excessive rate of weight gain manifested by young infants returning to the well-baby clinic at the Jessop Hospital (Taitz, 1971 ; Taitz & Harris, 1972). T h e third observation that we thought striking was the fact that many mothers were starting cereals and even meat and other baby foods as early as the first week of life. In order to elucidate the nature of the intake of the infants that we were studying, we obtained a series of random urine samples from breast-fed and artificially fed babies at the age of 6 weeks, and also of milk that the mothers had prepared to feed their babies when they brought them to the clinic. The results of these investigations have been reported elsewhere (Taitz & Byers, 1972), but are summarized in the accompanying table What we have demonstrated is that the concentrations of creatinine and uric acid in the urine of breast-fed babies compared with babies fed on cow's milk formulas indicate that the urine volume of the latter group is considerably lower than one would normally expect. We have also shown, as expected, that the solute excretion of breast-fed babies is much lower than that of artificially fed infants. Attention has recently been drawn once again to the high solute load of cow's milk feeds (Shaw, Jones & Gunther, 1973). We have also been