The breast milk the baby gets at the beginning of a feeding session is called the “foremilk,” which is more watery and high in volume but low in fat. As the feeding progresses, the fat content of the milk rises steadily as the volume decreases. The milk near the end of the feeding is low in volume but high in fat and is called the “hindmilk.”
While there are two different names for the two types of milk, there’s no magic moment when foremilk becomes hindmilk. As the baby breastfeeds, the increase in fat content is gradual, with the milk becoming fattier and fattier over time as baby becomes closer to draining the breast.
Knowing that there are two different kinds of milk has created anxiety in many women — it’s easy to start to worry about whether baby is getting “enough” of the fatty hindmilk. But this isn’t something you need to be concerned about. It’s the total milk consumed daily — not specifically the hindmilk — that helps baby gain a healthy amount of weight. Whether babies breastfeed often for shorter periods or go for hours between feedings and feed longer, their total daily fat consumption does not actually vary.
So don’t worry about how much hindmilk your baby is getting or try to coax her to feed longer. As long as baby breastfeeds effectively, until she’s satisfied, and you don’t regularly cut feedings short, she’ll receive about the same amount of milk fat over the course of a day no matter what her breastfeeding pattern. This is because the baby who breastfeeds more often consumes foremilk higher in fat than the baby who breastfeeds less often. So in the end it all evens out.