Not only does early nutrition affect later development, but also, during infancy eating habits are established that will affect nutritional status for a lifetime. A baby grows faster during the first years of life than ever again. The birth weight doubles around four months of age and triples by the age of one year. After this, the growth rate slows considerably.
The energy nutrients and the vitamins and minerals particularly crucial to the growth process eg. vitamins A and D, calcium and iron are most important. The most important nutrient of all, is the one most often overlooked – water. The younger the child the greater percentage of the body weight is water and the more rapid the turnover. Conditions that cause fluid loss, such as vomiting, diarrhoea, sweating and urinary loss without replacement can rapidly result in dehydration. Fluid and electrolyte imbalances, caused by infection, kill more children worldwide than any other disease or disaster.
In early infancy, breast milk or formula normally provide enough fluid for a healthy infant, but if the weather is extremely hot or the infant has diarrhoea or vomiting, then extra water is required. Supplemental water is required by all infants once solid foods are commenced. Breast milk is tailor made to meet the nutrient needs of the human infant.
The carbohydrates of breast milk is lactose, the fat is a mixture with plenty of the essential fatty acids and the protein, alpha-lactalbumin is easily digested by the infant. Vitamin C content is good and better than cow’s milk but Vitamin D is low. The minerals of breast milk are readily absorbable and in the correct proportions to allow for growth.
Besides nutrients breast milk offers many other beneficial substances. During the first two or three days of lactation, the breasts produce colostrum, a substance which contains antibodies and white blood cells from the mother. Colostrum is relatively sterile and thus helps protect the newborn infant from those infections against which the mother has developed immunity.
These diseases are the ones in her environment and are therefore precisely those for which the infant needs protection. Colostrum and breast milk contain factors which promote the growth of beneficial bacteria in the infant’s digestive tract (lactobacillus bifidus). Breast milk also contain lactoferrin which aids the infant’s iron absorption and acts as an antibacterial agent. Other factors in breast milk include enzymes, hormones and lipids which all help protect the infant against infection. Even a few weeks of breast feeding will give the infant the immunological protection and other special growth factors as well as significantly reducing the infant’s likelihood of developing an allergy to cow’s milk when it is introduced.
Once a baby is obtaining about 1/3 of its daily energy requirement from a balanced mixture of cereals, vegetables, fruits and other foods, then whole cow’s milk can be introduced. Undiluted cow’s milk should not be given before about six months of age, because the infant’s digestive tract may be sensitive to its protein.