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What's so unique about breast milk?

what's so unique about breastmilk
what's so unique about breastmilk

Your breast milk is totally unique to you. Its composition is determined by your diet, hormones, genetics and environmental influences. Amazingly, it also changes with you and your baby’s individual needs.

Tailor-made for your baby

It is not yet known exactly how breast milk is innately tailored to you and your baby. That’s why we’re committed to continuous research into this natural marvel. However, we do know that the fat content of breast milk increases during each feed1. It also changes to reflect environmental factors, so it contains more water if the weather is hot2.

Breast milk produced for boys
contains 25% more calories

Baby boys consume more of their mother’s milk than girls3,4. And surprisingly, the breast milk produced for boys contains 25% more calories than for girls5,6

Breast milk composition

Research has shown that 87.5% of breast milk is made up of water7. The rest contains different components, including various carbohydrates, fats, proteins and minerals. During a feed, breast milk changes colour and becomes thicker as the amount of energy it contains gradually increases1.

Around 87.5% of breast milk is made up of water.

Complete nutrition

‘Foremilk’ – the first milk of a breastfeeding session is packed with all the carbohydrates, protein and vitamins a baby needs. As a result of its high water composition, it also protects exclusively breastfed babies from dehydration1,8.

The ‘hindmilk’ produced towards the end of a breastfeeding session looks thicker and is darker in colour. This is because its energy and fat content increases as the feed goes on, allowing babies to take on enough energy to go longer between feeds1,8.

The first milk of a breastfeeding session is packed with all the carbohydrates, protein and vitamins a baby needs.

Providing protection from birth

But it does more than provide complete nutrition. Breast milk is filled with germ-fighting antibodies9.

Your gut bacteria is transferred to your baby’s gut through breast milk. However, just how this works is yet to be discovered10,11.

Worried about breastfeeding?

It’s completely normal to find breastfeeding a little tricky at first, but our breastfeeding guide is full of tips and advice to help you succeed.

View references

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1. Mizuno et al. Is increased fat content of hindmilk due to the size or the number of milk fat globules? Int Breastfeed J 2009;4(1):7.

2. Solter A. The Aware Baby. California: Shining Star Press, 2001.

3. Michaelsen KF et al. The Copenhagen Cohort Study on Infant Nutrition and Growth: breast-milk intake, human milk macronutrient content, and influencing factors. Am J Clin Nutr 1994;59:600-11.

4. Butte NF et al. Infant feeding mode affects early growth and body composition. Pediatrics 2000;106(6):1355-66.

5. Thakkar SK et al. Dynamics of human milk nutrient composition of women from Singapore with a special focus on lipids. Am J Hum Biol 2013;25:770-9.

6. Powe CE et al. Infant sex predicts breast milk energy content. Am J Hum Biol 2010;22(1):50-4.

7. Riordan J. Breastfeeding and Human Lactation. 3rd ed. Boston: Jones & Bartlett, 2005.

8. Hartmann PE. Mammary gland: Past, present, and future. In: Hale & Hartmann's Textbook of Human Lactation. Amarillo, TX: Hale Publishing, 2007. p. 3-16.

9. Chirico G et al. Antiinfective properties of human milk. J Nutr 2008;138(9):1801S-6.

10. Fernández L et al. The human milk microbiota: Origin and potential roles in health and disease. Pharmacol Res 2013;69(1):1-10.

11. Jeurink PV et al. Human milk: a source of more life than we imagine. Benef Microbes 2013;4(1):17-30.

Last reviewed: 10th March 2016

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