Breastfed babies do not gain weight, can be considered with physiological factors, improper feeding, micronutrient deficiency and other reasons. 1. Physiological factors: the baby in the first week after birth, can be due to meconium discharge, water loss, milk intake is insufficient, physiological weight loss, but after the birth of the 7th to 10th weight can be restored. 2. Improper feeding: babies in the growth and development period, due to gastrointestinal digestion and chewing function is not yet sound, due to improper feeding, can lead to digestive disorders, weight will not grow. 3. Micronutrient deficiencies: such as zinc deficiency, can affect the baby’s intelligence, metabolism, growth and development, etc., zinc intake is insufficient, due to growth and development is affected, the child is short, growth retardation. When the baby’s weight does not grow or even decline, it is recommended to go to the hospital specialist in time, after clarifying the cause of the disease, the cause of the symptomatic treatment, in order to prevent the impact on the child’s health and growth and development.