Four-month-old babies can tentatively add complementary foods, but it is generally recommended to start adding from six months. Four months of the baby’s gastrointestinal function development is not perfect, can be a small amount of supplemental food added tentatively, but does not affect the normal amount of milk. If you add too much supplemental food, it is easy to cause indigestion, and even vomiting, diarrhea and other symptoms, causing intestinal damage. Generally formally add complementary foods from six months, when the baby usually gastrointestinal digestive function development is more perfect, can tolerate complementary foods. And six months after the baby’s growth and development faster, and breast milk nutrients began to decline, timely addition of complementary foods, to provide the growth and development of nutrients needed. The addition of complementary foods need to consult a professional doctor, not blindly add their own to avoid harm to the baby.