Infant Feeding

Dear Lisa,

My baby is constantly eating. He takes 3 to 4 ounces of formula every 3 hours and always seems to look for more. How do I know if I am feeding him the right amount of formula?

“How much formula should I give?”

Dear “How much formula should I give?”,

Most babies will give their mother cues when they are finished with a feeding. Usually a baby will turn his mouth away or fall asleep when he is full. If your baby is content after feeding and he has 6 to 8 diapers wet with urine in a 24 hour period, then he should be drinking enough. Your doctor can track your baby’s weight gain at regular intervals during infancy at his well baby examinations. As long as your baby gains weight at regular intervals and maintains his percentile curve on the weight growth chart he is eating enough.

It is important to remember that infants have a normal need to suck. It is a normal part of their development during the first 6 months of life. In infancy, a baby feels with his mouth the way that an adult feels with their fingers. Therefore the mouth and sucking are central to all of an infant’s activities and learning. In the first 6 months, sucking is the most satisfying activity performed by an infant. It is through sucking that an infant gains nutrition, satisfies hunger and learns. Infants need a minimum of 2 hours of sucking per day, including feeding time. (1) This sucking can be fulfilled through feeding and by allowing an infant to suck on a pacifier.

Some parents interpret an infant’s need to suck as hunger. Therefore if a baby starts sucking on his hand or rooting (turning his head to the side with his mouth open) and it is not time for a feeding it is a good idea to allow the baby to suck. It is normal for parents to question, how do I know if it’s time for a feeding or if my baby just wants to suck? The normal time interval between feedings is 2 to 3 hours for breastfed babies and 3 to 4 hours for bottle fed babies. When you measure the time interval between feedings, you should start from the beginning of the feeding not the end. Therefore if a breastfed baby begins to eat at 6 a.m. and finishes eating at 6:20 a.m. the time for the next feeding should be at 8 a.m.

Some parents feel better knowing the exact number of ounces of formula they should give their baby. There is a calculation that healthcare professionals use to determine if an infant is receiving the sufficient amount of calories. Babies need 50 calories per pound of body weight per day. If you have an 8 pound baby boy, he needs 50 calories X 8 pounds = 400 calories per day. Regular baby formula has 20 calories per ounce therefore you need to divide 400 by 20 to determine how many ounces of formula the baby needs in a 24 hour period. 400 divided by 20 = 20 ounces. The results show that an eight pound baby needs 20 ounces of formula per 24 hours or 2 ½ ounces per feeding if a baby eats every 3 hours. If you are concerned that your baby is not getting the correct amount of baby formula, you can input your child’s weight into this formula and discuss the results with your Doctor or Nurse Practitioner.

Premature and low birth weight babies have special requirements and their calorie intake should be closely monitored by a healthcare professional. A low birth weight baby is defined as one with a birth weight of less than 2,500 grams( or less than 5 pounds, eight ounces). In this situation, many times the Doctor or Nurse Practitioner will prescribe special infant formula with more calories per ounce (24 to 27 calories per ounce). Low birth weight and premature babies also typically require more calories per day as compared to a full term baby; approximately 110 to 150 calories per kilogram per day.

(1)Chow M, Durand B, Feldman M, Mills M. Handbook of Pediatric Primary Care. Albany, New York: Delmar Publishers Inc. 1984: 283-284.

Lisa Kelly RN., P.N.P.,C.
Certified Pediatric Nurse Practitioner

Pediatric Parenting Advice