Formula Feeding: Newborn Digestion Time Explained

Newborns have their first meal within the first few hours of life. They can only consume breast milk or formula during the early months because they cannot yet chew or swallow solid food. Formula-fed babies consume about half an ounce of formula in those early hours, and this amount increases to two ounces every two to three hours as the baby grows.

On average, it takes a newborn's body about three to four hours to digest infant formula. In comparison, breast milk is digested in about 1.5 hours.

Newborns consume half an ounce of formula in the early hours after birth

In the first few hours of life, a newborn will have their first meal. If formula-fed, they will consume about half an ounce of formula during those early hours. From that point on, every two to three hours, a newborn will consume about two ounces of milk, whether from breast or bottle. As the baby continues to grow, their stomach begins to expand. By the end of the first week, many babies are eating twice as much.

On average, it takes 78 minutes for half the contents of a baby's stomach to empty after a feed of infant formula. This is compared to 48 minutes for breast milk. After one hour, an average of 22.7ml of infant formula per 0.1m2 of body surface area will have emptied from the stomach.

It takes about 24 hours for milk to complete its course through a baby's digestive system and eventually lead to a bowel movement.

Most newborns eat every two to three hours, or eight to twelve times over 24 hours. However, each baby is different, and their feeding patterns may change as they grow.

Formula-fed babies consume 2 ounces of milk every 2-3 hours

In the first few days after birth, a newborn will consume about half an ounce of formula. From that point on, every two to three hours, they will consume about 2 ounces of milk. As the baby grows, their stomach expands, and they will gradually be able to consume more. By the end of the first week, many babies are eating twice the amount they did at birth.

It's important to monitor a baby's weight gain to ensure they are consuming enough formula. Growth spurts typically happen when a baby is 2 to 3 weeks, 6 weeks, 3 months, and 6 months old. Additionally, it is crucial to pay attention to their feeding cues, such as sucking on their lips or tongue, putting their fingers in their mouth, or crying.

It is recommended to feed a baby on demand, which means watching for these cues to determine their hunger level. Most newborns eat every 2 to 3 hours, or eight to 12 times over 24 hours. However, each baby is different, and their feeding patterns may change as they grow.

Breast milk is digested in 1.5 hours, while formula takes 3-4 hours

The rate at which food is digested and absorbed varies depending on its composition. Breast milk is more easily digested by babies than formula milk. This is because breast milk contains enzymes (amylase and lipase) that aid digestion. These enzymes are not present in formula milk, which is usually based on cow's or goat's milk, or soy.

Breast milk is digested in approximately 1.5 hours, while formula milk takes approximately 3 to 4 hours. This is due to the curds formed in babies' stomachs by the protein in breast milk being softer than those formed by the protein in formula milk.

Additionally, the protein in formula milk is only partially digested and absorbed into the baby's system. About half of it passes through the baby's body as waste. This is why formula-fed babies tend to have larger and firmer stools than breastfed babies.

Formula should be discarded if it's been out for 1 hour at room temperature or 24 hours in the fridge

The time it takes for a newborn to digest formula depends on the type of milk the baby is fed. Breast milk is digested in a shorter time (approximately 1.5 hours) compared to infant formula (approximately 3 to 4 hours).

Formula feeding a newborn requires careful attention to safety. It is important to note that prepared formula should be used within one hour from the start of a feeding session or within two hours of preparation if it has been left at room temperature. If you’re not giving the bottle to your baby within two hours, it is crucial to refrigerate it and use it within 24 hours to prevent contamination.

• Always wash your hands with soap and warm water before preparing the formula.
• Clean the formula can and opener before opening. For powdered formula, wash the top of the can with soap and hot water, then rinse and dry.
• Use clean bottles and nipples, and wash them after each use.
• Start with water first, then add the formula powder.
• Measure the water and formula powder precisely according to the manufacturer's instructions.
• Do not dilute the formula by adding extra water, as this can lead to nutritional deficiencies or seizures.
• Shake the bottle gently to mix the formula evenly. Avoid using a microwave to heat the formula, as it can create hot spots that may burn your baby's mouth or throat.
• If your baby is under three months old, was born prematurely, or has a compromised immune system, boil water and let it cool for five minutes before mixing with the formula.
• Always do a temperature check by placing a few drops of the prepared formula on your wrist before feeding it to your baby.
• Serve the formula within two hours of mixing or within one hour of starting a feeding session.
• Refrigerate any leftover formula and use it within 24 hours.
• Throw away any formula left in the bottle after feeding, as the combination of baby saliva and formula can promote bacterial growth.

By following these guidelines, you can ensure that your newborn receives safe and nutritious formula feeding while reducing the risk of contamination and promoting proper digestion.

Formula-fed babies have larger, firmer stools than breastfed babies

On average, it takes a newborn around 3–4 hours to digest formula. Within 24 hours of birth, a baby passes meconium, a sticky, tarry substance made of amniotic fluid, mucus, and skin cells. After this, the baby's intestinal tract begins to digest formula, which takes longer than the digestion of breast milk.

Formula-fed babies tend to have larger and firmer stools than breastfed babies due to the difference in protein content and digestibility between breast milk and formula. Formula-fed babies' stools are often described as being similar in consistency to peanut butter.

Protein Content and Digestibility

Breast milk contains less protein than infant formula, but virtually all of the protein in breast milk is digested and absorbed into the baby's system. In contrast, only about half of the protein in infant formula is digested, with the rest passing through the baby's body as waste.

Enzymes

Breast milk also contains enzymes (amylase and lipase) that aid digestion, whereas infant formula does not. As a result, babies can digest breast milk more easily and in a shorter amount of time (approximately 1.5 hours) compared to formula (approximately 3–4 hours).

Nutritional Composition

The nutritional composition of breast milk changes throughout the day and the course of lactation to meet the evolving needs of the growing baby. This dynamic composition ensures that the baby receives the precise combination of water, carbohydrates, protein, fats, vitamins, minerals, enzymes, and antibodies it needs at each stage of development.

Frequently asked questions