Human milk changes in its composition throughout lactation as your baby grows and is constantly changing to meet the needs of the baby from the first few days of colostrum to beyond the baby’s second year. The composition of your milk can change from day today especially as hormones ab and flow with your menstrual cycles. They can change during a given day based on your stress levels, how often your baby feeds, and how well your baby MDs your breast. But did you know that the composition of your milk can also change during an individual feeding and from breast to breast?!?! As the baby eats, protein and fat content rise in the milk. There is actually 4 to 5 times more fat and 1 1/2 times more protein present at the end of the feeding than at the beginning. The baby may consume nearly 18% of their calories between minutes 11 and 16 of a feeding. The fat content at the beginning of a feeding is around 1% milk fat. By the end of a 15 to 20 minute feeding, the fat content can be as high as 4 to 5%! By comparison, whole milk contains just 3.25 percent milk fat. Fat content varies from mother to mother and from feeding to feeding. The amount of fat in breastmilk is dependent on the length of time between feedings, the degree of breast fullness, and the length of time the baby sucks at the breast. To put it simply, the emptier the breast, the higher the fat content. The fuller the breast, the lower the fat content. By trying to “stretch” a baby to scheduled feedings actually decreases the fat content in a mothers milk. It is always best to feed baby on demand.
Fact of the day: Human milk has one of the highest levels of lactose among mammals: 7%. Lactose accounts for almost all the carbs in breastmilk and provides 40-50% of the energy in the milk. Lactase is the enzyme naturally produced in the body to convert lactose into simple sugar. This enzyme is prevalent in our bodies at birth but it’s production lessens after age 3. Up to 70% of the world’s adult population has a lactase deficiency, which is indicative of the body maturing and no longer needing human milk as the primary source of nutrition. It is rare for children under 3 to have lactase deficiency, reflecting the biologically normal age for weaning.
As mamas we all have the same fear: are we making enough milk to keep our tiny humans alive? In the pumping room at work I get this question in all of its forms multiple times a week. With the advent of formula feeding, we have even more question and doubts about our body’s natural ability to produce for our offspring. First of all, we need to stop comparing breastmilk to formula. They are not the same. No matter how good the marketing is, formula can never compare to breast milk. Breast milk is a living, changing tissue. Formula is static and produced. Did you know formula fed babies take an average of 33% more volume per day than breastfed babies? Why? Because their bodies are only half as effective at processing it than formula. They basically need to eat more to get the nutrients and calories they need for growth. The human body was designed to consume breastmilk, therefore it is the perfect balance of calories, fat, and protein and can be maximally digested and used as fuel in the body.