I am afraid that this is one of the most common misconceptions about breast milk, a misinformation that has no scientific basis. Under normal circumstances, from birth to six months, a newborn baby can get all the nutrients needed for growth by relying exclusively on breastfeeding, without adding any supplementary foods, including water. After six months, the baby’s growth needs nutrients, relying solely on breast milk is not enough, you need to add supplementary food. The reason why complementary food is called “complementary” food is precisely because it is a food that assists breast milk. Until the baby is one year old, breast milk is still the main food and source of nutrition. Each mother’s breast milk is specially designed for her baby and will change as the baby grows to meet the different needs of the baby at different times. For example, when the baby’s body is attacked by a new germ or virus, the new enemy is transmitted to the mother’s body by sucking on the breast milk. The mother’s body immediately makes immunoglobulins in response to the “enemy” and transmits them to the baby through the breast milk, creating a barrier in the baby’s body to protect it from infection. 6 months is not the absolute bottom line, some premature babies or babies with allergies refuse or cannot accept complementary foods due to physical reasons, and rely exclusively on breastfeeding until 8 or 9 months or even longer, but they are still well nourished and growing strong. I know a pediatrician whose youngest baby, because of allergies, was exclusively breastfed until the age of two before she started eating solids. In fact, until the beginning of the last century, the vast majority of babies were exclusively breastfed until they were one year old. To date, there is no scientific evidence that breast milk loses its nutritional value at any stage, but on the contrary, numerous studies have proven that breast milk is rich in nutrients, such as fat, protein, calcium and vitamins, etc., no matter what time of the year it is, especially immune factors that are vital to the child’s health. A young child’s own immune system is not sound until about six years old, and until then, long-term breastfeeding is equivalent to establishing a natural immune barrier for the child, which can effectively prevent many diseases. This is why authorities such as the International Health Organization, La Leche League International and the U.S. Department of Health recommend that mothers around the world insist on breastfeeding until their children are two years old or even longer.