Final answer:
The correct introduction of solid foods to an infant is achieved by introducing one new food at a time and waiting several days before introducing another, to monitor for allergies or digestive issues. Whole cow's milk is not an appropriate first food due to its challenging composition for infants, and breast milk should remain a key part of the diet. Breast milk evolves from colostrum to mature milk, changing within each feeding from watery foremilk to creamy hindmilk.
Step-by-step explanation:
The correct understanding of introducing solid foods to an infant is reflected in the response: "I'll introduce one new food at a time and wait several days before introducing another." This approach allows parents and caregivers to monitor for any potential allergic reactions or digestive issues that may arise with each new food. Introducing solid foods should start around 4-6 months of age, and they should complement breast milk or formula, not replace them entirely. Whole cow's milk is not recommended as a first food source for a baby because it contains less lactose, less fat, and more protein and minerals than breast milk, making it difficult for an infant's immature digestive system to metabolize and absorb. Moreover, the proteins in cow's milk can be particularly challenging for infants to handle.
The composition of breast milk changes significantly over the first days and during a single feeding session. Initially, a lactating mother produces colostrum, which boosts the newborn's immune system with high levels of immunoglobulins. After approximately three days, transitional milk is produced, followed by mature milk around the tenth day postpartum, which offers the perfect balance of nutrients catered to the infant's developmental stages. During feeding, the foremilk satisfies the infant's thirst with its watery and lactose-rich content, whereas the hindmilk that comes later is creamy and fat-rich, helping satisfy the infant's appetite.