Human breast milk is not always the same. Your milk is different from the milk of other breastfeeding people. There are a lot of reasons for this variation, but your milk is also different from YOUR other milk! Your milk will change throughout the months, weeks, days, hours and even minutes that you are breastfeeding. Even during one breastfeeding session, your milk will change. That’s because you have foremilk AND hindmilk.

Foremilk and hindmilk are different, but each plays an important role in nourishing your growing baby. Recognizing the differences and understanding how to achieve a balance between these two can be helpful so you can ensure that your baby is getting optimal nutrition.

What is foremilk?

All of the milk is essentially the same. All of the components are there at all times. It’s best to think of it just as a difference in proportions. Foremilk comes first during a feeding. It’s the appetizer or salad course. It’s light, nutritious, refreshing, and provides great hydration. Because it is more watery, its primary job is to quench a baby’s thirst.

Foremilk is also most rich in lactose, the natural sugar found in milk. It’s also rich in proteins and vitamins and other healthy and necessary components. The high levels of lactose give your baby a quick boost of energy at the beginning of a feeding so they can get started well and then continue to feed until the end.

The color of foremilk may appear bluish or watery. Foremilk is first because it’s the thinnest and easiest to get out. As the breastfeeding continues, the milk will change by getting fattier and thicker. By the time the baby needs to start working extra hard to get the thicker milk out, they have plenty of energy to keep going because of the foremilk.

What is hindmilk?

As your baby continues to feed, the fat and calorie content will gradually begin to increase. At the end of the feeding, the milk is generally creamier in consistency and higher in fat content. The higher fat content in hindmilk contributes to the baby’s overall calorie intake and helps the baby gain weight.

The richer milk also helps the baby feel full and stay satisfied for longer. Hindmilk has many of the same components as foremilk, with the addition of more of the essential fats required for brain development, immune system support, and the overall growth of the nervous system.

When does the milk change?

This depends on each breast and each baby. Some babies are very fast and efficient eaters and can get through ALL the milk very quickly. Others take longer. Sometimes there is a lot of foremilk, and sometimes very little. It depends on the person, but also it can depend on how long it has been since your baby’s last feeding and whether they finished the feeding at the time.

If it hasn’t been long, and the baby got cut short at the last feeding, there may be less foremilk and more of the hindmilk that wasn’t taken out at the last meal. It may also depend on how much milk you have overall. If you have a surplus of milk, there may be a lot more foremilk before the hindmilk fully emerges.

What does this mean for my breastfeeding?

Honestly, this is interesting information, but it just doesn’t really mean much for your daily breastfeeding experience. You don’t need to control the way your baby feeds so they can get more or less foremilk or hindmilk. Babies need all of it, and the best way to ensure that they are getting enough of what they need is to allow the baby to lead the way. Let the baby decide when to eat and for how long on each breast.

It’s best not to control the amount of time spent on each breast since everyone is different. It may take more or less time to get all the milk from each breast. It depends on the breast, the milk supply, the time of day, and how efficient the baby is. Try to trust the process. It’s designed to work.

There are some things that can interfere with the balance of foremilk and hindmilk. If you take the baby off a breast before they are ready, they may not get the full spectrum of milk. It also means the breast doesn’t get fully emptied which can be a signal to your body to scale down the milk production because it wasn’t all needed. You especially don’t want to do this if you’re trying to increase or maintain your milk supply.

Too much stimulation can also lead to an oversupply of milk. If you are doing a lot of feeding AND a lot of pumping, this can lead to an oversupply of milk. Sometimes, this oversupply will lead a parent to move the baby to the other breast after what they think is too long on the first breast. It’s best to just be patient and wait until the baby decides to finish so that it’s more likely that they get all the milk.

In general, we know that hindmilk takes longer to get out than the foremilk. That’s because it’s thicker. It’s often true that a lot of what you have left in your breasts by the evening is hindmilk. It might be that your feeding sessions during the day get cut shorter, or you might spend more time during the day pumping instead of directly feeding your baby, especially if you’re at work. If you notice that your breasts seem less full in the evening, it could be that there is more hindmilk and less foremilk.

If you notice that your baby wants to breastfeed for a VERY LONG TIME in the evening, that might be because the hindmilk is thicker and takes longer to draw out. It’s a great idea to go ahead and let your baby get as much as they want. That belly full of fatty milk might give everyone a longer piece of sleep before the next feed!

How does pumping affect this?

Pumping is usually not as effective as a baby in removing milk from the breast. Babies tend to be faster, stronger, and more likely to draw out all the milk. A lot of times pumped milk has less of the hindmilk, especially if you’re not quite pumping long enough.

When you look at a bottle of breastmilk, after a little while you’ll see that the thicker milk rises to the top, while the more watery part stays at the bottom. Some people have a thicker layer than others. This does not necessarily mean that there is an imbalance.

Some people just make fattier milk in general. What matters most is that your baby is happy and growing. If you are giving bottles of breast milk, and you’re wondering if it’s too watery, it might mean that your baby just needs a little more milk to feel satisfied.

Some people prefer to mix all of their pumped milk together and then pour it into bottles so that it’s more uniform. That’s a fine thing to do if you really want to, but may not be really necessary. Your baby will eventually get all of the milk you’ve pumped, and it’s normal for the milk to vary at each feeding. If you’re breastfeeding AND bottle feeding your pumped milk, it’s even less likely to be a problem.

True Hindmilk/Foremilk Imbalance

Although it’s very rare, there are some cases where there’s a true imbalance between foremilk and hindmilk. When the baby is getting more than the normal amount of foremilk, a baby might get too much lactose. This does not mean the baby is lactose intolerant, it just means that they are getting too much and it’s more than their body can properly digest. The symptoms of this lactose overload are gassiness, fussiness, extreme discomfort, and lots of green frothy poop. These babies might be gaining weight fine since they are getting plenty of calories, but something is just not quite right.

In this situation, it might be helpful to change some things about the way you’re feeding your baby. If you suspect that this is happening, definitely see a lactation consultant, because there are many things to consider before deciding on the best course of action.

References

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5673630/
https://breastfeeding.support/forget-about-foremilk-and-hindmilk/