Three-month old infants will eat approximately six times per day, with bottle-fed infants eating about 6 ounces per feeding, based on information provided by the Nemours Foundation and U. S. National Library of Medicine. Infants at this age will typically gain about 1.5 to 2 pounds per month, and grow about 1 to 1.5 inches per month.
As babies grow, the amount of feedings per day will decrease, while the amount of food taken in at each feeding will increase. Parents can also watch their baby's reaction to determine whether they are still hungry. Three-month old infants will get most of their nutrients from either breast milk or formula. After 4 months, parents may begin to consider whether the child is ready for solid foods.