Breast Milk vs Formula: How Do They Compare?
For many parents considering formula, a top concern is whether formula is really an acceptable replacement for breast milk. This may be one of the first choices a parent makes for their child, and it’s not surprising for them to wonder:
Are breast milk and formula actually similar? Will my baby still thrive if I use formula?
While we can agree that breast milk is the optimal first food for infants, we know that it’s not always possible or desired to provide it exclusively. As such, let’s take a look at how breast milk and formula compare from a nutritional standpoint.
What’s in Breast Milk?
Breast milk is complex and dynamic; it’s created to meet all of the nutritional needs of an infant from birth through 12 months. Additionally, breast milk changes in composition based on a baby’s age and health.
Like all milk, breast milk is made of water, protein, carbohydrates, fats, vitamins, and minerals.
Although the exact nutritional content of human breast milk can vary depending on how long a mother has been lactating and even the time of day, scientists have been able to approximate the quantities of the macro and micronutrients that are contained within it. These findings are based on several studies that analyzed the composition of breast milk among a large population of lactating mothers.1, 2, 3
While many of the components of breast milk can also be found in formula, there are certain features that simply cannot be replicated.1 These include:
- Bioactive molecules, such as those that contribute to immune maturation
- Variation due to the evolving nature of the mother’s diet or health
What’s in Formula?
While formula is not an exact approximation, rest assured that it is carefully crafted to contain all of the components that a baby needs to grow and develop. Just like breast milk, the basis of infant formula is water, protein, carbohydrates, fats (including omega-3 and omega-6 fatty acids such as DHA/ARA), vitamins, and minerals. Some formulas also contain prebiotics (specifically oligosaccharides) and probiotics (such as Lactobacillus) in order to mimic the immunity-boosting properties of breast milk. Additionally, formulas include a myriad of nutrients found in breast milk, including:
Linoleic acid, Linolenic acid, Vitamin A, Vitamin D3, Vitamin E, Vitamin K1, Vitamin C, Vitamin B1, Vitamin B6, Vitamin B12, Niacin, Folic acid, Pantothenic acid, Biotin, Calcium, Phosphorus, Magnesium, Iron, Zinc, Manganese, Copper, Iodine, Sodium, Potassium, Chloride, Selenium, Choline, and Inositol (WebMD)
Finally, the calorie count of a liquid shows the amount of energy that can be derived from it. As you’d expect, the calorie counts of both breast milk and formula are very similar. See the chart below for how three popular formulas compare to breast milk in terms of calorie content. NOTE: These values are estimates that have been published in scientific literature. It’s important to remember that the nutritional content of milk can vary slightly, depending on the mother’s diet. Mature breast milk is considered to be from day 10 of lactation onwards.
A Closer Look at Protein
Whey and casein are the two main categories of protein found in milk. Whey proteins are relatively small and are more readily digested and absorbed by the body, whereas casein proteins tend to be larger and require a longer time for metabolic breakdown. When a mother begins lactating, her breast milk initially has a very high whey-to-casein ratio: around 90% whey and 10% casein. This makes sense, considering that newborns require easily-digestible food with a fast absorption rate for rapid growth. As breast milk matures, its composition shifts to a more balanced ratio of approximately 60% whey and 40% casein.
For this reason, both HiPP and Holle modify the whey to casein ratio in their cow’s milk formulas in order to match the protein composition of breast milk.
The cow’s milk formulas made by both HiPP and Holle have a ratio of 60% whey to 40% casein, whereas Holle’s goat’s milk formula contains 20% whey and 80% casein. The higher whey-to-casein ratio in Holle’s goat’s milk formula is typically not a problem for digestion; the casein in goat’s milk is easier to break down and less allergenic than the beta-casein proteins found in cow’s milk. These differences in the type of casein help to offset the higher concentration, making the ratio in Holle’s goat’s milk formula suitable for infants.
The table below shows the amount of protein, in grams, found in breast milk versus our three popular formulas:
A Closer Look at Fat
The specific fatty acid profile of breast milk varies slightly from one mother to another based on her diet. However, all breast milk contains a variety of saturated, monounsaturated, and polyunsaturated fatty acids.
There are many types of fatty acids in breast milk that contribute to optimal infant growth and development.4,5 They include:
- Palmitic acid
- Stearic acid
- Lauric acid
- Oleic acid
- Palmitoleic acid
- Vaccenic acid
- Omega-6 fatty acids such as linoleic acid and arachidonic Acid (AA/ARA)
- Omega-3 fatty acids such as DHA
Therefore, infant formulas use a special blend of oils in order to approximate the fatty acid profile of human breast milk. Manufacturers often use skimmed milk instead of whole milk as the base for infant formula so that oil can be added to achieve a ratio that is closer to breast milk. Therefore, the use of skimmed milk in infant formula does not mean that the formula is fat deficient in any way.
Common fatty acids found in Holle and HiPP formulas include:
- Palmitic acid
- Oleic acid
- Linoleic acid
- Stearic acid
- Alpha-linolenic acid
Many of the fatty acids in breast milk are also found in common vegetable oils, which explains why manufacturers have chosen vegetable oils as the fat-giving ingredient in infant formula.
It’s important to note that the omega-3 fatty DHA, which many people will recognize as a component of fish oil, contributes to cognitive development and healthy brain function in babies. In accordance with new EU regulations, DHA has recently become a mandatory fatty acid in European infant formulas.
The chart below shows the breakdown of fat levels in mature breast milk and our three popular European formulas:
A Closer Look at Carbohydrates
Lactose is the main sugar in most milks, including human breast milk, cow’s milk, and goat’s milk. As a carbohydrate, lactose is used by the human body for energy.
Human breast milk is relatively rich in carbohydrates, especially when compared to cow’s milk and goat’s milk. As a result, most formula companies add additional carbohydrate sources to their product to more closely resemble the composition of human breast milk. This can be accomplished by adding carbohydrates such as lactose or maltodextrin to the formula mixture. In HiPP formulas, additional lactose is added until the levels are near that of human breast milk. With the exception of Holle PRE, Holle formulas contain maltodextrin, which is easily broken down for energy needs. This is similar to the starch found in many foods, such as potatoes.
Regardless of the source of the carb, breast milk and formula contain similar levels of carbohydrates per 100mL:
As you can see, the nutritional value of formula is incredibly similar to breast milk as it relates to calorie count, protein content, fat content, carbohydrates, and overall nutrient profile. While some variation exists between formula and breast milk, variation also exists between women and in their breast milk over time. Given this comparison, you can rest assured that formula provides the foundational nutrition your baby needs to thrive.
Have questions about which formula is right for your baby?
We produced a special Organic Formula Buyer’s Guide with all the need-to-know information about our top European formulas. It’s easy to skim with comprehensive notes to make your life easier! Additionally, our team of Product Specialists will work with you to determine the formula that best meets your baby’s needs. We love to talk with moms about the amazing products we offer! Contact us here or shoot us an email at firstname.lastname@example.org. We can’t wait to help!
Macronutrient approximations taken from: