A four-year-old child who has been sick for a month has been unable to gain weight because of a low calorie intake or excessive calorie consumption, not excluding conditions such as wasting disease. If you want to gain weight, you need to make sure that the calorie intake is greater than the body’s daily calorie consumption. A four-year-old child who has been sick for a month and has not been able to gain weight may be consuming too few calories. In this case, it is appropriate to increase the intake of calories, let the child eat more high protein, high vitamin food can be, such as beef, eggs, broccoli and so on. However, if the excessive consumption of calories is caused by disease, you need to be alert to tuberculosis and other wasting diseases. Such diseases may additionally consume a lot of calories from the body, which in turn leads to the four-year-old child’s weight not going up for a month after the illness. The four-year-old child’s weight after a month of illness has not gone up may also be caused by other reasons, it is recommended that once you find a child with similar symptoms, take the child to the doctor in a timely manner, improve the relevant examination, targeted treatment and treatment.