The weight gain of a normal full-term newborn is between 10-30g per day, with an average of 20g per day, which is normal as long as it is more than 600g per month. Weight gain is the most objective indicator to determine whether a newborn is feeding properly. If a newborn’s weight gain is less than 20g/day, it is considered as slow weight gain, which can cause malnutrition in serious cases, and it is recommended to consult a doctor to find the cause. It should be noted that some newborns have a physiological weight loss period about one week after birth, during which their weight does not increase, but decreases, with a decrease of less than 10%.