Estimated reading time: 11 minutes
Updated December 2015
Photo: Anna Bondarieva
An examination of what is and what isn’t important in the breastfeeding mother’s diet for her own and her baby’s nutrition.
My Twitter account name is “_breastfeeding.” There, I see mainly three types of posts relating to maternal diet during lactation: (1) women delightedly calling for more cookies, (2) bitter complaints that long periods of breastfeeding did not lead to any weight loss, and (3) warnings that one has to avoid eating a wide range of foods that can cause symptoms in the nursling.
There can be no doubt that junk food, fast food, heavy consumption of snack foods high in refined carbohydrates, fat and salt, and reduced exercise are the main cause of the shocking obesity epidemic that has gained momentum in the USA over the past 30 years.
Probably, as has been true for me for much of my life, many readers are aware of and have largely ignored the concept of “empty calories.” But the bald, cold-shower truth is that every time we consume alcohol (7 cal/g), sugar, and other refined carbohydrates (4 cal/g), and fat (9 cal/g), we are giving our body two choices: (1) nutrient deficiency or (2) having to eat much more to obtain necessary nutrients, risking weight gain.
Refined carbohydrates have a rebound effect that makes us soon want more, depending on how much is eaten in what kind of meal, that is, how rapid the increase of the resulting insulin response is. Fat is somewhat better than it looks because some types are nutritious and even required (see below on DHA) and it does have an appetite-suppressing effect. So if you eat according to appetite (a good idea) fat in the diet may be useful, but high levels of refined carbohydrate in the diet are indeed linked to unwanted weight gain. Whole grains are unrefined carbohydrates and include brown rice and whole wheat flour. Be careful though because “wheat bread” may only contain some whole wheat. Look for 100% whole wheat; healthy bread does not feel like a sponge when you gently squeeze it.
I show only one movie to all my undergraduate and most graduate classes in nutrition when we are discussing obesity: “Super Size Me.” It is, of course, an exaggerated case study, but is full of good public health nutrition messages and warnings. One of the more shocking scenes is where the dietitian shows the filmmaker that, in spite of eating double his needs, nearly 5000 calories a day, his McDonald’s diet has failed to come even close to meeting his daily needs for most nutrients.
The lactation period, especially the first year, is a time when women not only have to recover from pregnancy and birthing, but they have to manufacture and provide the nutrients and energy contained in the world’s only perfectly balanced food. Yes, you can eat more than you otherwise do without gaining weight. But no, filling those extra needs with cookies is not a good idea.
How much extra should mom eat?
The US Recommended Daily Allowance for a breastfeeding mother has long hovered around 500–600 extra calories a day, but there are so many factors to take into account that this is almost useless knowledge. How much food you need depends on how much breast milk you produce (influenced by the baby’s age, whether you are breastfeeding exclusively in the first six months, and how intensive breastfeeding is after that), your body size, and percentage of body fat, how much weight you gained during pregnancy, your age, how much exercise you take and whether your goal is to gain, lose or maintain your weight, and how rapidly. Given all that variation, it would take a very detailed workup by a highly qualified dietitian to estimate how many calories you ought to eat. And let’s be honest, who sticks to such a plan for any length of time, even if she does all the hard work required to count all their calories honestly every day? I recommend ignoring calories and instead concentrating on (1) getting 30–60 minutes of moderate exercise daily, (2) eating adequate amounts of natural, healthy food, high in dietary fiber and low in refined carbs, that provides the nutrients you need and stops you feeling hungry half the time, and (3) not drinking calories unless they are in low-fat milk or occasionally in fruit juice (100 percent juice, not a juice beverage).
From a purely biological perspective, weight loss is a rare crisis. Losing more than 10% of one’s body weight without intending to is usually a sign that we are dying of something very serious. During lactation is not a good time to try to lose weight. Like any biological process, there is much variation from person to person, but if you exercise and eat a healthy diet nature intends for you to lose the extra weight you put on during pregnancy during the few years nature intended for your child to get breast milk. Nature’s goal is for us to attain a healthy weight as we grow up, if possible to put on a few extra pounds (or even kilos) to protect us, in case we are subject to short periods of famine, and then to more or less maintain that weight throughout our lives.
Does mom have to restrict her diet to avoid allergies in her breastfeeding child?
The short answer, based on the evidence available right now, is no. The causes of allergy are still poorly understood. Particularly with respect to more severe lifelong allergies like asthma, it is just not clear what role breastfeeding and the maternal diet play during lactation. The UK National Health Service used to counsel avoiding peanuts while breastfeeding, but recently rescinded that advice because there simply was too little evidence that there was any impact.
If mother, father or siblings suffer from serious allergies you may want to avoid any foods known to cause symptoms. Otherwise, just watch for early signs of allergy in the baby (unexplained skin rashes, often on the cheeks). Some babies become colicky (lots of unexplained crying, usually at night), but that, of course, can have other causes. Then gradually eliminate one likely cause at a time from your diet. The baby’s symptoms will usually subside in a few days if you have found the right one.
I would start with fluid cows’ milk if you drink a lot of it. Other dairy products are much less likely to cause problems. Then, reintroduce the eliminated food to your diet to see if the symptoms recur. If so, you can be pretty sure you’ve found an allergen. You should avoid introducing that food to your child early in infancy and introduce it with great care later.
One of the nastier lifelong types of food intolerance is to gluten, a protein found in high quantities in wheat and in lower concentrations in some other grains. Gluten intolerance or celiac disease, once it starts, never goes away, and it’s difficult to diagnose, especially in babies. However, it appears that the best way to reduce your baby’s risk is to introduce wheat to her diet while she is still getting a large amount of breast milk.
Does mom have to restrict her diet to avoid colic in her breastfeeding child?
It’s common on the Internet to read advice to breastfeeding mothers to avoid (or restrict) intake of caffeine, as well as garlic, broccoli, beans, and dairy foods, to avoid gas in the baby. A colicky baby is no fun, but no one knows whether avoiding a wide range of nutritious foods like this has any substantial impact on the likelihood of your baby getting colic. We do know that restricting the diet so radically has an impact on the mother’s nutrient intake, so I would on the whole recommend NOT trying to avoid such a wide range of foods, even in the early months when colic is more common.
Babies under six months need only breast milk
Unfortunately, the ancients did not understand or adequately respect the concept of exclusive breastfeeding. In particular, the Humoral Theory—along with the similar concepts promoted by traditional medicine in India and China, probably the most widely shared belief system in the world until about a century ago and still widely influential—considers colostrum to be harmful and recommends such hazardous prelacteal feeds as honey. Probably because of this theory, it is still common in much of the world to use herbal teas to treat or even prevent colic and other symptoms. But the infant liver simply cannot cope with many of the substances in herbs that are perfectly safe after infancy, and the resulting mild to moderate liver damage may in turn be behind many unexplained cases of illness and malnutrition in infants. The bacterial spores in honey can cause fatal disease in infants because they don’t yet have stomach acid strong enough to kill them. Thus, preventing the use of honey, herbs, gripe water, and other traditional treatments for infants, especially in younger ones, needs to be a major goal for breastfeeding counsellors in many cultures.
The main public health impact of maternal nutrition during lactation relates to perceptions, not reality
Warning a mother not to drink much alcohol during breastfeeding may lead to women deciding to avoid breastfeeding or to breastfeed less. Yet a message is needed because alcohol is slightly harmful to breastfeeding babies and to the breastfeeding process. The younger the baby and the more the mother drinks the greater the risks. The common advice to take a beer before each breastfeed is based on a myth—unless it’s alcohol-free beer, which may perhaps have some benefit.
There is good evidence that mothers easily (and incorrectly) take on exaggerated beliefs that their breast milk will be poor in quality or low in quantity because of their inadequate or poor diet. In some studies, this appears to be a major cause of early supplementation, especially with infant formula. This is one example of how easily a mother’s confidence can dip, especially in settings (which seem to me to be pretty universal) where women are already made to feel self-conscious about their bodies.
I came across a shocking example when I did my first breastfeeding research in St. Vincent, West Indies, in 1975. In interviewing all women with one-year-old babies in two towns, I found that virtually all did non-exclusive breastfeeding for ￼￼￼￼￼￼￼￼￼￼an average of eight months. (There was a local belief that breastfeeding ought to stop by nine months.) The most common supplement was glucose water, given to all babies born at the local hospitals. Its label claimed it was helpful against a long list of diseases. Most mothers also added some formula early in the baby’s life. When I asked mothers what would happen if a baby got nothing but mother’s milk for five months, 40% were worried the breast milk might not be enough, but 60% said it would be good. When asked why they did not feed that way, 60% said, “I couldn’t afford that.” They then showed me the brightly colored Nestlé brochure that they received from the local clinics. Its centerfold consisted of a photo of the meat, fish, milk, and eggs, which made up the 3000-calorie diet they would need to eat to make “good breast milk.” “So I just topped up with Lactogen,” or, “I realized that if I have to drink milk to make milk, I might as well give it directly to the baby,” they told me—an effect of the brochure that Nestlé was probably the only one to understand.
Studies in both traditional and modern cultures have found that the perceived insufficient milk syndrome was the greatest barrier to exclusive breastfeeding. And the greatest cause is often thought to be the mothers’ concern that they ate poorly or even just ate too much “snack food” to be able to make enough milk. I expect the perception that one’s breast milk will either be inadequate in quantity or quality unless one can eat as well as the high-class mothers shown on breastfeeding posters (especially the ones sponsored by formula companies) is very common everywhere.
The fact is that, although it’s not going to be good for anyone’s health in the long run to eat a poor diet, it has very little if any impact on breast milk quantity.
What about quality?
That’s a more complex picture. Levels of protein, lactose, most minerals, and some vitamins are relatively fixed in mother’s milk. If the mother gets too little in her diet, she will suffer, but her breast milk will not be affected. But there are a few exceptions of potential importance:
- Mothers rarely have enough vitamin D to produce breast milk that will provide the vitamin D babies need. Sun exposure of mother and baby can help, but is not recommended because it is too difficult to know how much is needed without risking skin cancer. Safest is to give babies vitamin D drops. Mothers who do not want to do so might try taking a supplement of 4000 IU of vitamin D3 daily, which early research suggests is safe and adequate. More on this complex issue
- DHA can be low in breast milk and the ratio of n-6 to n-3 fatty acids will also be too low in breastmilk if mothers do not consume enough in their diet. A European food safety agency recently recommended that breastfeeding women consume at least 200mg/day but one gram a day is probably wiser. Certain fatty fish are the only good dietary sources (salmon, sardines, and tuna are the most popular). Here again, supplements might be a good idea for many mothers.
- Vitamin B12 can be obtained reliably only from animal foods (including dairy products) and breastfed babies can develop severe deficiency and permanent nerve damage if levels are too low in breast milk. Vegans should thus take supplements.
- Iodine and selenium are crucial minerals but, being highly water soluble, they easily wash away in large geographical areas. If there’s too little in the soil, then there’s too little in the plants and animals that live there. If a mother is deficient, she is likely to have too little in her breast milk but, at least regarding iodine, the main harm to the baby already occurs during pregnancy. Since almost no one gets too much and the only really good dietary source is certain types of seaweed, we should all eat iodized salt. Selenium research is at too early a stage to know how common deficiency is or to figure out how best to prevent it besides eating a wide variety of foods coming from different geographical regions. The best dietary source is Brazil nuts. It is widely found in other plant and animal foods, including nuts, cereals, meat, fish, and eggs.
We all need routine exercise and to eat healthy, natural food—a diet composed largely of vegetables, fruits, whole grains, legumes, low-fat dairy products, and perhaps seafood. I have mixed feelings about including seafood in the list since some, especially freshwater fish in some areas and seafood from polluted coastlines, can contain levels of heavy metals and other toxins that pose a health risk.
When it comes to human milk, nature is robust and your diet will not affect how much milk you produce and, apart from the exceptions mentioned above, will not have much effect on its quality. If you cannot afford to eat a healthy diet, or feel stressed to think about having to eat in a more healthy way during breastfeeding, it’s best to forget that for now (and the breast milk quality issues above can be dealt with through supplements, which some, who can afford them, may find to be a less stressful approach).
Just go ahead and breastfeed as much and for as long as you and your baby want to. You’ll be giving your baby the best food she can get, irrespective of what you eat.
Ted Greiner, PhD, is Professor of Nutrition in the College of Human Ecology at Hanyang University, Seoul, South Korea. He was at Uppsala University Medical School in Sweden for 19 years, where he was Associate Professor of International Child Health. His main areas of research have been linked to unraveling the reasons for suboptimal breastfeeding and finding ways to improve things. Most of his and his graduate students’ writings are available in full text on his website.