Breastmilk and Your Diet

"The composition of breastmilk is relatively independent of what the mother eats, breastmilk contains hundreds of items including live cells, that will never be a part of formula and that the biochemistry of formula is entirely different from that of breastmilk. Eating "poorly" does not cause the immune factors (including the antibodies) from breastmilk, nor the stem cells, nor the prostoglandins, nor the white cells and dozens of other important ingredients to disappear from breastmilk. Proteins, sugars, fats and other nutrients in breastmilk are "high quality" no matter what the mother eats."

Dr Jack Newman.


A question I get asked frequently relates to breastmilk and one’s diet. A lot of women are concerned how their diet will affect the nutritional components of their breastmilk. This blog will answer how one’s diet affects breastmilk, what is needed for maintaining an ample supply of milk, and are there certain foods that should be avoided when breastfeeding.

Pregnant women usually pay very close attention to their diet since every food, drink, and medication ingestedmay make its way to the developing baby. Fortunately, this is not exactly the case with breastmilk.

Breastmilk is produced from the mammary glands in your breasts, not directly from the substances you ingest (Yay!!) These glands draw on the resources available in the form of nutrients from your diet and from your body’s stores of nutrients. Luckily Mother Nature is quite forgiving. A mother’s milk is designed to provide for and protect the baby even in times of hardship and famine. If your diet contains insufficient calories or nutrients to sustain both you and your baby, your mammary glands will have “first shot” at your body’s available nutrients to produce highly nutritious breastmilk, leaving you to rely on whatever is left over (not always the greatest thing for mom). So a less-than-ideal diet will probably not affect your breastfeeding baby, but it may leave your body at nutritional risk.

According to Katherine A. Dettwyler, Ph.D., breastfeeding researcher and anthropologist, women throughout the world make ample amounts of quality milk while eating diets composed almost entirely of rice (or millet or sorghum) with a tiny amount of vegetables and occasional meat. I tell my clients all the time when they ask me about their diet and breastmilk production that for centuries, women in third world countries have survived on a bare-minimun diet, and still seem to find a way to produce and provide nutritionally balanced breastmilk for their infants.

The breasts are actually very smart. The mammary glands and cells that produce milk also help to regulate how much of what you eat and drink actually reaches your baby. Moderate consumption of caffeinated beverages, and occasional glass of wine or other alcoholic beverage are fine when you are breastfeeding. However, some babies are more sensitive than others, so keep a close eye on your baby and see if she is acting any differently after consuming certain foods/beverages.

So what is needed for maintaining an ample supply of milk? The main thing needed is quite simple. It’s called supply and demand. The more often and effectively your baby breastfeeds, the more milk you will have. An exclusively breastfeeding mother, on average, needs to take in 300-500 calories/day above what was needed to maintain her pre-pregnancy weight. Since the recommended added calories during the last 2 trimesters of pregnancy is 300 calories/day, an exclusively breastfeeding mother will typically need either the same amountof calories she was getting at the end of pregnancy, or up to 200 additional calories/day. That’s not very much. It is basically equivalent to an additional1-2 healthy snacks per day.

 The main message when it comes to calorie and fluid intake is to eat when hungry and drink when thirsty. When exclusively nursing a new baby, it is very common to feel hungry a lot of the time. I remember while nursing my last daughter Maya, that sometimes in the middle of the night I would feel so ravenous that I would send my husband downstairs to bring me a protein bar or a sandwich. You may also feel hungrier when your older baby goes through a growth spurt and temporarily wants to feed more frequently. Bottom line....listen to your body!!!  Oh.....BTW, drinking more milk does not help your body make more breastmilk and vitamin and mineral supplements are not considered necessary if you are eating a reasonably well balanced diet. Your fat intake does not affect the amount of fat in your milk, but can affect the kinds of fats (balance of good vs. bad fats) in your milk to some extent. I will delve into this a little deeper in a bit.

If you really want (or need) to count calories, studies show that most healthy women maintain an abundant milk supply while taking in 1800-2200 calories per/day. Consuming less than 1500-1800 calories per day, may put your milk supply at risk, as may a sudden drop in caloric intake. A mother’s “baseline” need for calories depends on her activity level, weight, and nutritional status. A mother who is less active, has more fat stores, and/or eats foods higher in nutritional value may need fewer calories than a mom who is more active, has fewer fat stores, and/or eats more processed foods.

It is not necessary to force down extra fluids either while breastfeeding. Again, drink to satisfy thirst.  Breastfeeding mothers are sometimes warned that “Only water counts!” when it comes to fluid intake, but this simply doesn’t make sense. You body can utilize water from many other sources, including vegetables, fruit, soup, water, fruit and vegetable juices, milk, tea and other beverages. The food you ingest accounts for about one-fifth of total fluid intake. Some fluids are certainly more nutritious than others, but even soda will provide fluids you need (but may also provide you with other things you don’t like extra sugar and caffeine!)

Let’s have a discussion about fat in breastmilk as it is a highly talked about topic. The average calorie content of human milk is 22kcal/oz. Caloric content varies widely throughout each feeding and the day. This is actually due to changing fat content. The amount of fat in human milk also changes dramatically during each feeding and throughout the day. Since fat content depends on the degree of emptiness of the breast (empty breast= creamier, fattier milk, full breast=lower fat content. The average fat content of human milk is 1.2 grams/oz.

So what affects the amount of fat in your breastmilk? The research tells us that a mother’s diet does not affect the average amount of fat or calories in her milk. However, a mom can change the types of fat in her milk by altering the types of fats that she eats (Lawrence 1999, p.106-113, 300-305; Hamosh 1996, Hamosh 1991, p.123-124). An increase in one fatty acid could generally be expected to occur concurrently with a decrease in another. For example, one study has shown that black mothers in South Africa who eat a traditional maize diet have less monounsaturated fatty acid in their milk than urban mothers who consumed more animal proteins and fats (van der Westhuyzen 1988). The degree of emptiness of the breast is what research has shown to drive breastmilk fat content, and thus calorie content. The fuller the breast, the lower the fat content of the milk; The emptier the breast, the higher the fat content (Daly 1993). I use this very interesting fact as a teachable moment with almost all my clients. A lot of moms get worried when their initially very-full-breasts suddenly become soft most of the time, they fear something has happened to their milk supply. I reassure them that as long as their baby continues to gain weight and settle after feeds, that soft breasts are a good thing......because they contain creamier, fattier milk. Another quick little tip is that breast compression (while breastfeeding) has been shown to increase fat content of milk (Stutte 1988). This is another one of my favourite teachable moments. Almost all my clients are taught and encouraged to do breast compression in the first few weeks after delivery.

 Are there certain foods that should be avoided while breastfeeding? To answer that question simply....NO. There are no foods that a mother should avoid simply because she is breastfeeding. It is generally recommended that you eat whatever you like, whenever you like, in the amounts you like and continue to do so unless you notice an obvious reaction in your baby to a particular food. There is no list of banned foods for breastfeeding women.  Even foods that are known to be gas causing have no more potential to affect your baby than other foods. Eating certain foods may cause gas in mom due to the normal breakdown of some undigested carbs (sugar, starches, soluble fiber) by bacteria in the large intestine. However, breastmilk is made from what passes into mom’s blood, not what is in her stomach or digestive tract. Neither gas nor the undigested carbohydrates (whose breakdown can cause gas in mom) pass into the mother’s blood. So it is impossible for these things to pass into your milk to make your baby gassy.

 But.....I know there is always a but. An unhealthy diet often means unhealthy gut, which is irritated and lacking in the healthy bacteria it needs to function optimally. I do believe the health of your digestive tract is tied closely to the health of your baby’s gut, which has lifelong implications. The better the health of your gut, the more effectively you are digesting all the food you take in and the fewer irritating proteins you pass through your bloodstream to your breastmilk. Your baby benefits from the greater availability of nutrients, less irritation in his digestive tract, and a variety of components that support normal development of his digestive system.

That about sums it up for this edition of ‘Let’s Nourish Our Babies: A Breastfeeding Blog’. I hope you found this blog helpful and informative. I am always happy to answer any of your breastfeeding related  questions or concerns. Knowledge is power and I hope I have been able to share a little more knowledge with you today in order to make your breastfeeding journey the best it can be!!!

Happy Breastfeeding and Happy Eating!!!!

Leanne R Rzepa RN BN IBCLC

Posted on January 17, 2016 .