Final answer:
Babies should be exclusively breastfed until 6 months of age, with breastfeeding continuing alongside complementary foods until 2 years or more, depending on individual preferences and circumstances. In the U.S., the mean weaning age is around nine months. Breast milk's composition adapts over time, providing important antibodies and nutrients.
Step-by-step explanation:
It is recommended that babies be exclusively breastfed until the age of 6 months. Following this period, the World Health Organization suggests continuing breastfeeding along with appropriate complementary foods up to 2 years of age or beyond. However, this differs based on regional practices and individual circumstances. For instance, La Leche League International highlights that the mean age of weaning worldwide is four to five years. In contrast, data from the United States suggests an earlier weaning age, with a survey indicating a mean age of nine months with a standard deviation of four months.
Additionally, during the first weeks of a baby's life, breastfeeding involves adjustments in milk supply to meet the infant's demand, resulting in approximately 1.5 liters of milk produced per day for a single infant. Over time, the composition of breast milk changes to suit the baby's developmental needs, offering a balance of nutrients and antibodies that provide passive immunity.