Breast milk is the ideal food for babies. The WHO and other scientific societies recommend that infants up to 6 months of age drink only breast milk and then continue breastfeeding, along with other foods, until 2 years or more as long as the mother and baby wish.
And it is that breastfeeding has multiple well-studied benefits. Babies who drink breast milk have less otitis, less gastroenteritis, and fewer lower respiratory infections ; they also have a lower risk of obesity and diabetes in the future as well as a lower incidence of sudden infant death . Mothers who breastfeed have a lower risk of postpartum hemorrhage, ovarian cancer, or diabetes.
Regarding its composition, breast milk provides all the nutrients that are needed to grow in the first months (and years) of life; But it also has an almost magical characteristic that makes it unique: it is capable of varying its composition, adapting to the infant at all times ; changes throughout breastfeeding, during the day and even during feeding.
What is breast milk made of?
We have already mentioned that breast milk undergoes changes in its composition and we will analyze them later. Mature breast milk is mostly made up of water (around 88%).
7% are carbohydrates (the majority is lactose) and between 3-4% fat (it is the component that varies the most in its composition) . Only 0.9-1% are proteins ; within them we have some with a fundamental role, such as lactoferrin, which helps the absorption of iron and prevents bacteria from using it, or immunoglobulins, which protect the baby against certain infections.
In addition, breast milk contains all the vitamins and the necessary amount of minerals . Breast milk is low in iron, but its absorption is much better than formula or cow’s milk.
How does breast milk vary throughout feeding?
In this viral video published by Steph Merrick, lactation consultant, we can see in a very graphic way how the composition of breast milk changes during feeding. Through a simple experiment, even if I speak in English, you can appreciate the three phases perfectly.
Throughout the intake, breast milk varies its composition. The breast is never completely emptied and most of the amount of milk, once breastfeeding is established, is produced during feeding. Roughly speaking , the first part is rich in water and sweeter (since it contains more hydrated carbon), while the final part is rich in fat and therefore more caloric and more satisfying. In reality, we can distinguish three “different milks” in the same intake.
- The first part is the one that the infant obtains with the least effort since it benefits from the ejection reflex . It is something that happens naturally. When the baby begins to suck, the brain releases a hormone called oxytocin that helps the milk come out; Oxytocin can also be released by other stimuli, such as a baby crying, looking at a picture of you, or sex. The ejection reflex is bilateral, that is, it affects both breasts at the same time, which is why it is common for one breast to leak when the baby is nursing on the other hand.
In this first phase, water is the main component and covers the hydration needs of the infant who is fed on demand. This portion is rich in carbohydrates (around 7%), most in the form of lactose. It also has bifidus factor , necessary for the growth of bifid flora. Other fundamental components of this first portion are protective factors such as immunoglobulins and lactoferrin, some hormones (which among other things help intestinal maturation), anti-inflammatory components and growth factors.
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The baby continues to suck, now with slower and deeper suctions, and the milk progressively changes its composition. This second portion has a fundamental nutritional function and is very important for the growth of the baby. It is rich in calcium and phosphorus and contains many proteins, especially the so-called caseins.
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The final part constitutes the lipid phase; it is rich in fat , as we said at the beginning. It provides a large amount of calories and is very satisfying. It is denser and babies require more effort to obtain it. Some protest a bit, pull the nipple, or take more breaks. The fat in breast milk is in the form of globules surrounded by a special membrane that allows easy digestion and proper absorption. This last portion of the intake is rich in cholesterol and it seems that this early exposure to it helps its correct metabolism in adulthood. It is also rich in unsaturated fatty acids that are essential for the development of the nervous system and the retina. It also contains defense agents against bacteria.
So that you can understand it better, we leave you the same experiment carried out by @LactanciaMitos in Spanish, in which they explain everything perfectly.
Breastfeeding should be on demand
Years ago (and unfortunately some professionals still say so), it was said that breastfeeding should have fixed schedules (every 3 or 4 hours) and a certain duration (they usually say 10 minutes on each breast). If we have understood the previous explanation well, we will know that such breastfeeding cannot work.
Only the baby knows what milk he is getting and what need it must satisfy. The baby chooses the duration of the feed . Thus, if you are only thirsty, it is likely that you will just suck quickly and immediately leave the breast; I just needed the first part. On the other hand, if he is hungry he will take a full feed, and we do not know how long it will take him to reach the final part (rich in fat) or when he will be satiated. We have seen that the final part is more caloric and has a high fat content, essential for its growth, so it is important that the baby gets to take this part.
Although one breast may be sufficient (there are even women who only breastfeed from one, for example, in the case of a mastectomy), some babies want to suckle a little more from the second breast. I usually say it’s dessert (because it’s sweeter), or a little water to help digest that last thicker serving.
The baby must also choose the interval between feedings. It is likely that in summer, due to the heat, babies will take more frequent feedings (in some cases, they will only suckle due to thirst). There are also times when they need us to increase our production (growth crisis) and they will take more shots (the higher the suction, the higher the production).
How does breast milk change throughout breastfeeding?
As incredible as it may sound, the breast milk of mothers who deliver premature babies is different from those of full-term babies. It contains more protein, more fat and more calories, as well as more lactoferrin and more Immunoglobulin A; instead, it has less lactose.
The composition of breast milk also changes as breastfeeding progresses . Thus, the first days after delivery we secrete colostrum ; it is said to be the first vaccine, because it provides very high amounts of immunoglobulins, lactoferrin and oligosaccharides, as well as defensive cells; it has a lot of protein and less fat than mature milk, and it is easily digested.
Later we will have transitional milk (in which lactose and fat increase and therefore provides more calories) and finally, around 2 weeks postpartum, mature milk . When breastfeeding is prolonged beyond the year of life, contrary to what one might think, it increases its fat and calorie content. There is no doubt: breastfeeding above the year is still beneficial .
How does it change during the day?
Breast milk also varies its composition throughout the day. During the night, it increases its content in substances such as tryptophan and melatonin , which help to fall asleep and promote the regulation of the circadian rhythm. In addition, during the night more prolactin is released, the hormone responsible for lactation par excellence; night feedings thus ensure a correct production of breast milk; In addition, prolactin helps the mother’s sleep.
How do I know if my baby is getting enough?
It is one of the most frequent doubts of nursing mothers. and we cannot know exactly how much you are eating, but we do have indirect measures to know if you are eating well. First of all, I will say that there is no bad breast milk ; the vast majority of breastmilks feed.
Breast milk has a very similar composition in all women (removing the differences already explained if a premature baby is born or depending on the stage of lactation in which we are). Only extreme maternal malnutrition or some extremely rare maternal disease can cause breast milk that is not sufficiently nutritious.
On the other hand, I mention here that breast-fed babies don’t grow or get fat the same as formula-fed babies (but they do it the right way). Weight is a great indicator to know if our baby is eating well. We know that newborns lose weight at birth and usually regain it around 10-15 days of age.
When they lose more than 7% of their birth weight we must be very alert and review the breastfeeding technique and if they exceed 10% we must be even more cautious and it is likely that they will need to supplement breastfeeding temporarily. After these first days and during the first 6 weeks approximately, babies who are exclusively breastfed gain around 20g per day. Your pediatrician will be in charge of controlling the weight and its evolution (the growth charts also help us a lot).
Other data that help us know if you eat well is the number of diapers that you stain per day . After the first 2-3 days, they should wet between 5 and 8 diapers a day. Stools are also a good indicator; the first 48 hours of life they eliminate meconium (a black viscous stool that was filling his intestine); later (2-6 days old) they will have at least 3 greenish stools a day (called transition stools) and from then on they usually have at least 3 mustard yellow stools every 24 hours.
After six weeks the intestinal rhythm can be modified. On the other hand, babies who are eating well do between 8 and 12 feedings a day. At first the feedings can be long, because they require effort, they get tired and they are still learning to breastfeed. Between takes they tend to fall asleep. And finally, the general condition of the baby is also essential. A happy, active infant with good color is likely to be eating well.
On the contrary, if your baby is lethargic, does not demand feedings and it is difficult to wake him up, he wets less than 4-5 pee diapers a day , does not eliminate meconium in the first 24-48 hours or does not perform a bowel movement daily, you think who is not gaining weight or gives you the feeling that you are not eating enough, you should consult your pediatrician.
In Babies and more | How to know if your baby is getting enough milk: seven signs that he is well fed
