After 4 months, the baby’s saliva secretion increases, amylase also increases, the stomach capacity increases compared to the birth, the gastrointestinal function gradually improves, and the baby has the ability to digest complementary foods. 6 months, the baby begins to grow teeth, and can gradually chew and digest some solid foods. Therefore, this period is more suitable to start adding complementary foods. Newborn babies can not digest foods other than milk, and the pancreatic amylase, which plays a major role in digestion, only starts to be secreted after 3 months, so adding complementary foods too early can easily lead to indigestion in babies. And the newborn baby will have a tongue reflex, that is, the tongue will be pushed out of the solid food into the mouth, if added too early supplemental food, easy to increase the risk of foreign bodies into the respiratory tract, which can lead to choking. If the baby has the desire to eat at 4 months, you can try to feed a small amount of egg yolk and liver puree to prevent anemia. 4-6 months is a critical period for the development of the baby’s chewing function, and if the baby is not given complementary foods and chewing training during this period, it will affect its development. Moreover, if complementary foods are added too late, babies may refuse to eat foods other than milk because of their habit and attachment to sucking breast milk, leading to difficulties in weaning and post-weaning feeding.