Breast milk is divided into foremilk and hind milk. When you hear your baby swallowing while breastfeeding, it proves that you are eating hind milk at this time, but the exact time cannot be generalized, it is related to the baby’s sucking power and the mother’s milk situation. Each time you breastfeed, the nutrients in the milk can change gradually as the milk is secreted. The first milk is lighter and less in volume, but contains relatively high protein and lactose. The hind milk is whiter, thicker and stickier, and contains more fat, which provides the newborn with the energy it needs and effectively improves the child’s hunger. The first milk can be sucked in a few minutes, while the second milk takes longer. Both the second milk and the first milk are essential for the child’s nutritional supply. During breastfeeding, women do not have to worry too much about the composition of breast milk, as it can be adjusted according to the nutritional needs of the fetus. As long as the mother maintains a varied and balanced diet after delivery, breast milk can provide all the nutrients and water needed for a child up to 6 months of age.