I've seen many mothers begin to add cereal to the just before night time feedings for babies who are large with quickly increasing appetites. My daughter wasn't a large baby but I do recall adding cereal to her feedings at about 4 - 4.5 mos. Just a little in the milk to create a bit more substance.
You can also discuss nutrition and feedings with the pediatrician with the baby's next visit. Some babies naturally need more than others earlier. Every baby is a bit different.





