For human babies, human breast milk is the ideal source of food and nutrition. Due to the chemical makeup of breast milk, health organizations around the world recognize the importance of it for young children. Breastfeeding is recommended exclusively for the first six months of life. After that period, breastfeeding is still recommended, along with the addition of solid foods, for a year, two years, or even longer.
Protein content is markedly higher and carbohydrate content lower in colostrum than in mature milk. Fat content does not vary consistently during lactation but exhibits large diurnal variations and increases during the course of each nursing. Race, age, parity, or diet do not greatly affect milk composition and there is no consistent compositional difference between milks from the two breasts unless one is infected. The principal proteins of human milk are a casein homologous to bovine beta-casein, alpha-lactalbumin, lactoferrin, immunoglobulin IgA, lysozyme, and serum albumin.
Breastmilk is uniquely superior for infant feeding. It is the normal food for infants from birth. Breastmilk contains all of the essential nutrients, antibodies and other factors important for growth and development.
Breastfeeding is the biologically normal way to feed babies. Hence, the composition of breastmilk is the biological norm for human babies. Breastmilk is a dynamic fluid which changes in composition over the course of lactation and varies within and between feeds and between mothers. Its composition also varies between term and preterm infants.