Unless there is a genuine contraindication (such as maternal HIV infection in the developed world), every baby should be breast-fed. The nutritional components of human milk are in the ideal proportions to promote the healthy growth of babies. The mother's milk, especially COLOSTRUM contains immune cells and antibodies that increase the baby's resistance to infection. From the mother's point of view, breast feeding helps the UTERUS to return to its normal size and aids the loss of excess fat gained during pregnancy. Most importantly, breast feeding promotes intimate contact between mother and baby. A point to be borne in mind is that some drugs taken by a mother can be excreted in her milk. These include antibiotics, sedatives, tranquillisers, alcohol, nicotine and high-dose steroids or vitamins. Fortunately this is rarely a cause of trouble. (See also main entry on BREAST FEEDING.)

Unmodified cows’ milk is not a satisfactory food for the human newborn and may cause dangerous metabolic imbalance such as HYPERNATRAEMIA. If breast feeding is not feasible, one of the many commercially available formula milks should be used. Most of these are made from cows’ milk which has been modified to reflect as closely as possible the composition of human milk. For the rare infant who develops cows’-milk-protein intolerance, a milk-based or soya-bean protein is indicated, and lactose-free milks are available for those diagnosed with lactose intolerance.

The main guide as to whether an infant is being adequately fed is body weight. During the first days of life a healthy infant loses weight, but by the end of the second week breast-fed babies should have regained their birth weight. From then on, weight gain should be approximately 6 oz. (170 g) each week for an average sized baby. Formula-fed babies gain weight faster than those who are breast fed – but this offers them no advantage.

The timing of feeds reflects social convention rather than natural feeding patterns. Among the most primitive hunter-gatherer tribes of South America, babies are carried next to the breast and allowed to suckle at will. Fortunately for developed society, however, babies can be conditioned to intermittent feedings.

As the timing of breast feeding is flexible – little or no preparation time being required – mothers can choose to feed their babies on demand. Far from spoiling the baby, demand feeding is likely to lead to a contented infant, the only necessary caution being that a crying baby is not always a hungry baby.

In general, a newborn will require feeding every two to four hours and, if well, is unlikely to sleep for more than six hours. After the first months, a few lucky parents will find their infant sleeping through the night.

Most babies will become dissatisfied with a milk-only diet at around six months, and will develop enthusiasm for cereal-based weaning foods. Also at about this time they enjoy holding objects and transferring them to their mouth – the mouth being an important sense organ in infants. It is logical to include food items that they can hold, as this clearly brings the baby pleasure. Introduction of solids before the age of four months is best avoided, firstly because it is unnecessary and secondly because it carries a small risk of danger from an intake that is too high in salt and too low in fluid. The usual reason given for early weaning is that the baby appears hungry, but crying or night-waking at this age is not likely to be due to hunger: crying due to COLIC, for example, is more probable. Some mothers take the baby's desire to suck – say, on their finger – as a sign of hunger when this is, in fact, a simple reflex.

Delaying the start of weaning beyond nine months is nutritionally undesirable. As weaning progresses, the infant's diet requires less milk. Once established on a varied solid diet, breast and formula milks can be safely replaced with cows’ milk. There is, however, no nutritional reason to stop breast feeding until the mother wishes to do so.

It is during weaning that infants realise they can arouse extreme maternal anxiety by refusing to eat. This can lead to force-feeding and battles of will which may culminate in a breakdown of the mother–child relationship. To avoid this, parents must resist the temptation to coax the child to eat. If the child refuses solid food, the meal should be taken away with a minimum of fuss. Children's appetites reflect their individual genetic structure and a well child will eat enough to grow and maintain satisfactory weight gain. If a child is not eating properly, weight gain will be inadequate over a prolonged period and an underlying illness is the most likely cause. Indeed, failure to thrive is the paediatrician's best clue to chronic illness.

Many sources of conflicting advice are available to new parents. It is impossible to satisfy everyone, and ultimately it is the well-being of the mother and infant and the closeness of their relationship that matter. In general, mothers should be wary of rigid advice. An experienced midwife, health visitor or well-baby-clinic nursing sister are among the most reliable sources of information.