11 months baby weight loss, usually with physiological factors, malnutrition and intestinal flora disorders and so on. 1. Physiological factors: most 11-month-old babies have learned to crawl, walk, if the usual activities are more, consume too much, the weight may fall, is a normal performance. 2. Malnutrition: If the baby’s appetite is not good, not in accordance with the requirements of eating, long-term dietary irrationality, resulting in poor absorption of nutrients; or milk powder is not brewed correctly or not added in a timely manner to complementary foods (6 ~ 8 months) may lead to nutritional deficiencies, so that weight loss. 3. Intestinal flora disorders: intestinal flora disorders, resulting in dysbiosis, causing diarrhea, may cause weight loss, and in severe cases will affect the resistance, immunity, easy to lead to physical weakness, poor mental state. 11-month-old baby weight loss, in addition to the above factors, should also be considered as a result of recurrent respiratory infections, zinc deficiency, calcium deficiency and other factors. However, it is not possible to analyze the cause of the disease based on the symptoms, and it is recommended to take the child to the hospital for examination in a timely manner to understand the cause of the disease and then carry out regular treatment.