It is normal for infants to gain 2 pounds per month in the first three months and more than half a pound per month thereafter. Babies can gain up to twice their birth weight in the first trimester, and from the fourth to the twelfth month the gain can be about equal to the birth weight. 1. If the baby’s weight gain is low, it is common for the baby to suffer from indigestion, breastfed babies may not have enough nutrients in their milk or the milk secretion is low, and supplemental food is not added at the right time. 2. If the baby’s weight gain is excessive, it may be due to excessive calorie intake or low activity level, etc., and we need to be vigilant about the weight gain caused by edema. Infants can go to the pediatrician for a physical examination, and under the doctor’s advice for dietary matching.