How Much Should a Newborn Eat?

Patient Presentation
A 4-day-old female came to clinic for her first visit. Her mother complained that she was a very spitty baby but wasn’t taking enough of her bottle feedings. The mother said she was told to give her 2-3 ounces of formula every 2-3 hours but she wasn’t taking all of it. “She’s only taking about 1.5 ounces and even then she seems to throw up with a lot of the feedings,” her mother said. “My mom says she needs to eat more too, but she just spits up,” complained the mother. The pediatrician noted that the mother kept trying to feed the infant when the baby clearly turned her head away from the bottle and didn’t want it placed back into her mouth. The past medical history showed a term infant born to a G1P1 mother without complications.

The pertinent physical exam showed a healthy appearing female with a weight of 3.873 kg which was decreased 2.1% from birthweight. Transcutaneous bilirubin was 6.8 mg/dL.
Her physical examination was normal except for mild jaundice around the face and upper trunk. During the examination, she had some effortless spit up of formula that did not bother her.

The diagnosis of a healthy, but being overfed infant was made. The pediatrician talked with the mother to help set expectations of how much the newborn would eat now and over the next couple of weeks and longer term. She also pointed out to the mother that the baby refusing the bottle was a cue to stop feeding the baby. “I think if you decrease the amount but keep feeding her fairly often she will be just fine and also won’t spit up as much,” counseled the pediatrician.

The patient’s clinical course at the next visit showed her to be above birth weight and gaining about 22 grams/day. The mother complained that she still had some spitting up, “but its a lot better. My mother still doesn’t believe you and thinks she needs to eat more. I just keep telling her that her grandbaby is okay,” her mother remarked.

A serving size and a portion are not the same thing. A serving size is a specific measured amount of food. This is cited on the product label or readily available resources such as cookbooks or the Internet (an example can be found here.) A portion is the amount chosen to be served or eaten by a person. They can be the same but may not be the same. For example, 4 ounces of cereal is a common serving size, but an adult may often eat more than this as their portion.

Children especially need appropriate portion sizes to match their age and body size. A good general rule for any age is a portion is the size of the person’s fist or palm of their hand. For example a 1-3 year probably would only need about 1/3-1/2 of a slice of bread but a 7-10 year old would need about 1 slice. Daily, the American Academy of Pediatrics recommends children should still get:

  • Meat = 2-3 servings
  • Dairy = 2-3 servings
  • Fruit = 2-3 servings
  • Vegetables = 2-3 servings
  • Grains = 6-11 servings

When having a meal, most people consume a few portions. This is usually not the total potential size of their stomach which leads to stretching and being uncomfortable and possibly even emesis.

Learning Point
Newborn infants on day of life 1 have unique needs as they are transitioning to extrauterine life. Importantly in those first few hours newborn infants must maintain glycemic control as hypoglycemia can cause organ damage. Infants who are stressed in some manner (e.g. presumed infection, respiratory distress, etc.) or who are known to have a higher risk of hypoglycemia (e.g. infant of a diabetic mother, large for gestational age infants, etc.) are monitored for hypoglycemia. Infants who have not fed for a long time or who have changes in mentation may also be tested for hypoglycemia. Glycemic control is usually achieved through the balance of glucose stores in the newborn’s body and oral intake through breast or bottle feeding. If an infant has true hypoglycemia, then intervention with oral or intravenous glucose may also be necessary.

How much does a newborn need to take or can even take given the size of their stomach? The stomach itself is also transitioning to extrauterine life. At birth, a small stomach size is expected and only needed.
The size of a newborn’s stomach is about:

  • DOL 1 5-7 ml, large marble
  • DOL 3 22-27 ml, ping-pong ball
  • DOL 10 60-81 ml, extra large chicken egg

Each infant will follow their own needs. On the first day of life the newborn cannot take much volume and needs to learn to feed through more frequent feedings, obtaining the small amount of colostrum that the mother begins to make highlighting the symbiotic relationship between the infant and mother. Over the next couple of days the stomach will expand, but a small amount of breastmilk or formula is still all that can fit into the stomach and small amounts frequently given should continue. Newborns often feed every 1-2 hours or so. Newborn infants over the next two weeks of life have their stomachs expand more so that 1-2 ounces in a feeding (when measured) are appropriate. Feeding at this time also often stretches the interval between feedings to 1-3 hours or so. It is important to follow the infant’s cues regarding feeding though as each infant is unique. When an infant is sated they usually slow down the rate of feeding, take longer pauses between sucking and will turn away from the breast or bottle. If the breast or bottle is re-offered they usually are uninterested. They often will be tired after feeding and fall asleep as well. When an infant is hungry, they will turn their head trying to find a nipple to feed, they may suck on their hands and often will cry to vocalize their hunger.

Overfeeding infants can easily occur with bottle fed infants. The food is easier to transfer from the bottle to infant and the infant cannot move away from the bottle as easily as they can from the breast. Therefore additional fluid may be transferred to the infant even if they are sated. It is not uncommon that parents will also complain that the infant is also spitting up too. The additional cost of formula can be an issue for many families as well. Animal studies and human studies have found that infants who are overfed, even at day 1, are at risk for overweight and obesity in early childhood. One study of formula fed infants in the Women, Infants and Children Special Supplemental Nutrition program (i.e. WIC) found that 37% of formula fed infants < 6 months old were potentially overfed consuming an additional 26 calories/day. This is an additional ~4800 calories over 6 months for these infants.

Questions for Further Discussion
1. How do you counsel parents of newborns to feed their infants?
2. Do family meals prevent obesity? A review can be found here
3. Do picky eaters really exist? A review can be found here

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Infant and Newborn Nutrition

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Portions and Serving Sizes – Accessed October 12, 2021.

Bergman NJ. Neonatal stomach volume and physiology suggest feeding at 1-h intervals. Acta Paediatr. 2013;102(8):773-777. doi:10.1111/apa.12291

Watchmaker B, Boyd B, Dugas LR. Newborn feeding recommendations and practices increase the risk of development of overweight and obesity. BMC Pediatr. 2020;20:104. doi:10.1186/s12887-020-1982-9

Anderson CE, Martinez CE, Ventura AK, Whaley SE. Potential overfeeding among formula fed Special Supplemental Nutrition Program for Women, Infants and Children participants and associated factors. Pediatr Obes. 2020;15(12):e12687. doi:10.1111/ijpo.12687

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa