The composition of breast milk is tailored to your baby! Y’all- the bond and synchronicity of you and your baby helps compose the breast milk to be exactly what it is. The infant helps determine the composition of the feed! I know this may seem nerdy but I think the science of breastfeeding is absolutely incredible. I feel like we already know that breastmilk has immune building factors and that it’s full of much needed vitamins and minerals for the baby. There’s so many other cool factors about the make up of the milk. With that being said, I want to share a few fun, scientific facts and how they ultimately affect your baby’s nutrition!

Colostrum (usually day 1 – day 4):

1) It has higher levels of protein and minerals, lower levels of carbs and fat (in comparison to transitional and mature milk) – this is why infants need so little in the initial days. Colostrum is thick and filling. 

2) It’s primary function is to be more immune building than nutritional.

Transitional Milk (usually day 5 – 2 weeks postpartum):

3) Similar to colostrum but also meets the nutritional needs of the baby.

Mature Milk (usually after 2 weeks postpartum)

4) Foremilk is the milk that is expressed at the beginning of the feed. Foremilk is thin and watery –  it takes care of baby’s thirst

5) Hindmilk is the milk that is expressed at the end of the feed. Hindmilk is thick and creamy. It contains more of the fat. – it takes care of the baby’s hunger

Pre-Term Milk:

6) Contains more protein and fat  (in comparison to full term milk) (1) – See! It was made to help build up the pre-term babe!

Breastmilk OVERALL:

7) Your milk changes to reflect the needs of the baby – I feel like I can’t hit on this ENOUGH. Mamas, your breastmilk is made for your baby. It changes for your baby. It adapts based on the needs of your child. 

8) It is digested more rapidly than formula. – this is why breastfed babies tend to feed more frequently 

9) Approximately 13% of breastmilk is solids (fat, protein, and lactose), which leaves the remaining 87% that is WATER! It’s not like the water that we drink though. It’s full of minerals and vitamins.

10) The percentages of the solids are approximately: 7% lactose, 4% fat, 1% protein. – That’s all, folks! A lot of moms worry about the fat content of their milk. In the grand scheme of things, the fat content is ONLY meant to be 4% of your milk and likewise with the other solids!

Composition of breast milk, breast milk composition, science of breastfeeding

Those are my 10 fun facts about the composition of breast milk! Comment below if your mind was kind of blown? Mine sure was whenever I first learned about the incredible acts that our body can perform!


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