Considering the complex nature of the human body, it’s no wonder breast milk is more than meets the eye. Though feeding your baby with the milk you produce seems like a very simple and straightforward process, the milk you are producing is actually very multifaceted. A friend of mine who insists on breastfeeding was recently telling me about the different types of milk that she produces at different times of day. Though the conversation was painfully intimate and slightly off-putting, I was endlessly interested in the fact that the breast could produce more than one type of breast milk. Most mothers learn about these two types of milk as they begin the breast-feeding process, but few understand how the two types are separately created.

Though it seems complicated, the process actually makes sense when you think about how the breast forms milk in the first place. When milk is made, it contains a watery portion called foremilk and a fatty portion called hindmilk. The foremilk contains more lactose. When milk is produced for the next feeding, the fatty cells stick to the walls of the milk ducts while the watery portion flows to the nipple. So, when your baby begins to breast feed, he will first receive this watery, lactose-filled milk that is ready to be expelled. During that process, the breast actually expels the rest of the hindmilk stuck to the walls and your baby receives the perfect balance of lactose for development and fat for growth.

Usually, your body automatically will produce the correct balance of foremilk and hindmilk. However, there are some instances when an imbalance occurs. Imbalances are usually caused by too much milk production. When your body starts producing too much milk, your baby will fill up on the watery foremilk before the nutritious hindmilk is expelled. Since the foremilk has a larger amount of lactose, you might end up overloading your baby’s system with it. Though the babies are fully capable of digesting lactose, they can’t handle too much.

As long as you follow a diet and feeding schedule that your doctor recommends, you probably won’t have an imbalance in the production of your breast milk. If your doctor notices that your baby might be getting too much lactose, you might be instructed to cut down on the amount of dairy you’re eating in your own diet so that your infant receives less lactose.

Source: Anne Walshaw: Are We Getting the Best from Breastfeeding? Acta Paediatrica Volume 99 Issue 9 pp. 1292-1297 September 2010