Best Breastfeeding Diet and Foods to Avoid

Can diet affect the amount or quality of milk a breastfeeding mother can make? Are there any foods to avoid while breastfeeding? What is the best breastfeeding diet? This article answers frequently asked questions about diet and breastfeeding.

Can my diet affect the amount of breast milk I can make?

Milk production is a complex process depending on milk removal from the breasts, diet and a number of other factors:

Can diet affect the quality of my breast milk?

Older text books state that a diet doesn’t need to be perfect to produce nutritious breast milk.1 However, the mother’s diet can affect breast milk composition in many subtle ways234, and more research is needed. For example:

  • Micronutrients in breast milk. If a mother is malnourished and/or if certain nutrients eg vitamin D, iodine or vitamin B12 (see below) are low or missing in her diet this will affect the availability of these micronutrients in breast milk.5
  • Food allergens. Breast milk can contain traces of food and occasionally a baby may be intolerant to something passing into a mother’s milk. Typically this will be a common allergenic food such as cows’ milk protein. See Milk Allergy in Babies for more information.
  • Fats in breast milk. Fats and fatty acids (the building blocks for fats) in our diet have important functions in the body and there are many different kinds. The composition of fats in breast milk depends on the fats a mother eats. See the next section for more on fats.
  • Microbiome. Fatty acid composition may also influence the breast milk microbiome (the microorganisms in breast milk).6
  • Breast milk flavour. Traces of a mother’s diet pass into breast milk and the milk is said to adopt the flavour of the food that the mother has eaten. This allows a breastfed baby to gradually become accustomed to family table foods and may help baby to accept a wide range of familiar tastes when solids are started.

Despite any slight differences in the composition of breast milk between mothers, it is still far superior to industrially made formula milk which has many missing ingredients and potential allergens.7 See Is There a Difference Between Breast Milk and Formula? for more reading.

How do the fats in my diet affect my breast milk?

Breast milk fat is a major source of energy, fat-soluble vitamins and essential fatty acids for the baby. There are different opinions on how the fat in a mother’s diet affects the fat in breast milk. Some authors state the fats a mother eats affects the type of fats found in her milk but not the total amount of fat in breast milk.89 Other authors state that the amount of fat consumed by a breastfeeding mother will affect the fat levels in her breast milk as well as the type of fat found in her milk.1011

Essential fatty acids

Some types of fatty acids are made within the breast, while others come from the mother’s diet. Long-chain polyunsaturated fatty acids (LCPUFAs) such as docosahexaenoic acid (DHA), ecosopentanoic acid (EPA), and arachidonic acid (AA) in breast milk come from the mother’s diet and are very important for the baby’s developing brain, eyes, nervous system and susceptibility to allergies during infancy. Consumption of fatty acids can also affect breast function and hence milk production (Lee and Kelleher, 2016). Koletzko et al12 found that some of the fat content of breast milk also comes from the mother’s body stores which will have been shaped by her past diet.

Low fat diet, low fat milk?

In her book Mother Food author Hilary Jacobson argues that a low fat diet could create low fat milk. One small study by Mohammed et al found that a higher fat, lower carb diet increased the milk fat, and energy content (calories) of milk compared to a lower fat, high carbohydrate diet of the same calorific value:

In conclusion, under moderate calorie restriction, milk production was not affected by maternal diet composition. Milk fat, energy content, and infant energy intake were higher during the [moderately high fat, controlled calorie] diet

Healthy fats

Healthy dietary fats are important for health and have crucial functions in the body. Research indicates that a diet that is high in carbohydrates (sugar, white flour and other refined grains) is associated with obesity, heart disease and diabetes rather than eating saturated or natural fats.131415 Examples of foods with healthy fats and fatty acids include grass-fed meat, oily fish, eggs, grass-fed butter, cheese, coconut oil, avocados, olives, nuts, and various seeds (Teicholz. 2015 p335; Jacobson, 2007 p35). Highly processed seed/vegetable oils are not healthy additions to dietary fat and lactation consultants Marasco and West note that trans-fatty acids (in hydrogenated oil) can reduce total milk fat in slim women, and that lower fat milk would mean more milk is needed to get the same calories (Marasco and West, 2020).

Research on fatty acids and maternal diet

Research is still discovering the importance of healthy fats in a mother’s diet:

  • Inflammation. One author discusses how an excess ratio of omega 6 fatty acids (found in many processed foods) compared to omega 3 fatty acids in a mother’s diet may be associated with inflammation including irritable bowel disease and recurrent mastitis. 16
  • Risk of disease. Researchers are looking into associations between the type of fats consumed in the mother’s diet, their metabolism, and the child’s risk of diabetes, asthma, or eczema.17

Variable fat content in breast milk

Irrespective of diet, the fat content of breast milk also varies during a single breastfeed and between feeds and breasts. Feeding on demand, and letting baby finish the first breast before offering the second, helps a breastfed baby get the milk (and fat) they need over a 24 hour period. Forget About Foremilk and Hindmilk has more information about how the fat content changes during a feed. If a baby isn’t gaining weight see How to Make More Milk and Baby Not Gaining Weight.

Are there any foods to avoid while breastfeeding?

A breastfeeding mother can eat and drink most things and there aren’t any specific foods to avoid as a general rule. It’s advisable to have a nutritious balanced diet because that is healthier for you, your milk supply and perhaps even your baby’s food preferences in the future—but generally you can eat your usual pre-pregnancy diet while you are breastfeeding.

What about baked beans, cabbage or spicy food…?

You may hear stories that you can’t eat certain food items when you are breastfeeding because they will give your baby tummy ache or wind (gas). Occasionally a baby may be sensitive to a particular food, or food group (dairy products can be problematic for some babies) but there’s no need to restrict your diet just in case.

What if my diet is mostly junk food?

A junk food diet is one that is high in calories due to a high sugar content and/or contains high amounts of unhealthy processed seed or vegetable oils.  Some breastfeeding authors state that eating a junk food diet will still produce good quality milk.18 Others question whether a diet of mostly junk food could predispose a baby to preferring junk food later in life.1920

Mother breastfeeding wearing head scarf
Occasionally a baby will react to something in his mother’s diet and she can then avoid that food for a while

Should I avoid allergenic food?

There are currently no recommendations to avoid typically allergenic foods such as nuts or fish during breastfeeding unless the mother is herself allergic to something that she needs to avoid.2122

Allergy author Maureen Minchin summarises:

in general, it is best not to exclude any foods from the mother’s diet, as breastfeeding is intended to create tolerance. In general, it is also best to exclude from the diet of the pregnant woman and breastfeeding mother foods to which she -and/or the biological father of the child – is clearly reactive

Can I eat peanuts while breastfeeding?

Yes, unless you know you are allergic to peanuts. The UK’s National Health Service (NHS) advises:

If you’d like to eat peanuts or foods containing peanuts, such as peanut butter, while breastfeeding, you can do so as part of a healthy, balanced diet (unless, of course, you are allergic to them).
There’s no clear evidence that eating peanuts while breastfeeding affects your baby’s chances of developing a peanut allergy. If you have any questions or concerns, you can talk to your GP, midwife or health visitor.

Can I eat fish while breastfeeding?

Fish is a good source of essential fatty acids for the breastfeeding mother however some types of seafood contain high levels of mercury due to marine pollution. Pregnant and breastfeeding mothers are advised to limit their potential exposure to mercury as it is particularly dangerous in the early stages of a baby’s development. The UK’s National Health Service recommends breastfeeding women eat no more than one portion of shark, swordfish and marlin per week because these fish can contain more mercury than other types of fish and no more than two portions of oily fish a week. There is no limit on canned tuna.23

My baby seems fussy, is it something in my breast milk?

There are several reasons why a breastfed baby can appear fussy so it is worth looking into these with your breastfeeding specialist or health professional before assuming something in your diet is the cause. Sometimes however, a baby can be sensitive or intolerant to particular foods which may cause them to fuss or have tummy ache. Other symptoms may be apparent such as eczema, reflux, rashes, being snuffly, copious runny poop and/or mucous in the poops.

Food intolerances

If your baby seems to be particularly fussy or uncomfortable after something specific you have eaten, try avoiding that food for a while to see if the symptoms settle down. A common culprit triggering a reaction is dairy produce in the mother’s diet see Milk Allergy in Babies. And see Elimination Diet for more information about cutting out problem food. In a discussion paper, Lindsey Hurd Reeves, researcher and IBCLC, reviews the relationship between maternal diet, a healthy immune system and a healthy microbiome and speculates how mother and baby’s gut function might be improved to reduce food sensitivities and allergy.24

Can I drink coffee or caffeine?

A few cups of coffee won’t normally upset your baby when you are breastfeeding. However caffeine does get into breast milk and can be difficult for a baby to metabolise (get rid of) especially in the first few weeks of his life. If you drink a lot of strong coffee, watch out for signs that your baby is particularly wakeful or jittery and read more about recommended daily limits in our article Coffee, Caffeine and Breastfeeding.

Can I drink alcohol while breastfeeding?

Small amounts of alcohol while breastfeeding do not pose a problem for your baby see Breastfeeding and Drinking Alcohol for recommended limits.

Can I take medications when breastfeeding?

Lots of medications are compatible with breastfeeding. For resources to check the compatibility of medicines see Medications and Breastfeeding.

Do I need to drink a lot of water?

You will probably find you are more thirsty than usual while breastfeeding. Drinking just enough fluid to quench your new thirst and ensure your urine is pale coloured will keep you well hydrated and provide enough liquid to make plenty of breast milk. There’s no need to drink huge amounts of extra water (or other drinks such as cows’ milk) to increase the amount of breast milk you make.25262728 Breast milk volume is increased by efficient and continual breast emptying, not by how much fluid you drink. One study by Dusdieker (1990) suggested drinking 25% more fluids than baseline may even reduce the volume of breast milk slightly.

You don’t need more fluids than you want in order to make milk, and your supply won’t decrease if you’re mildly dehydrated. If your urine is medium to pale yellow, then you’re doing fine. Oxytocin release can make you suddenly thirsty (carrying a water bottle helps).

In the latest edition of their book Making More Milk 2e, Marasco and West mention the possibility that drinking excess water could also cause swollen nipples and areolae which can compress milk ducts and slow milk flow.

Do I need to eat extra food while breastfeeding?

During the first four to six months of his life a baby will double his birthweight on breast milk alone. Your metabolism efficiently handles this energy requirement by using the fat stores laid down in pregnancy alongside eating around 500 extra calories a day.29 Women who are very underweight or malnourished with no fat stores may need to eat more than this.

Can I breastfeed if I am underweight?

Excessive dieting i.e. consuming less than 1500-1800 calories daily on a regular basis is said to reduce milk production (Marasco and West, 2020). Older resources frequently state that unless the mother is significantly malnourished she can often still make enough milk 30 but newer texts question whether the babies in these situations are growing to their full potential (Marasco and West, 2020). Very underweight mothers may have breast milk with low levels of some nutrients and fat. Improving the mother’s diet and vitamin status will raise the vitamin levels in breast milk.

Because micronutrient levels are quickly reflected in breast milk, renourishment of the woman is effective for mother and infant. It is less expensive and safer to nourish the mother than it is to give the infant artificial baby milk

Very underweight mothers will not have substantial fat stores to draw on for the additional calorific demands of breastfeeding and may need more calories from their diet.

burger in a bap

Can I breastfeed if I am overweight?

With good help from your IBCLC lactation consultant breastfeeding will have the best chance to get off to a good start whatever your size. Considerations for overweight mothers include:

  • Studies suggest breast milk can be later “coming in” when a mother is overweight with a pre-pregnancy BMI above 2731 or 3032 and an overweight mother may have a lower prolactin response in the first week after birth affecting milk supply33
  • Some underlying causes for obesity (BMI above 30) may be associated with low milk supply e.g. polycystic ovary syndrome, hypothyroidism, insulin resistance or diabetes.34
  • Overweight mothers may be at risk for nutrient deficiencies, which may contribute to low milk supply, if they consume a very poor diet35 or had gastric bypass surgery (Marasco and West. 2020. p95).
  • Diabetes. Animal studies indicate that maternal obesity and overeating of calorie rich foods could be associated with a higher risk of obesity and type 2 diabetes in the offspring.36
  • Not all women who are overweight experience problems with breastfeeding3738 However barriers to success can include discrimination and lack of support for common challenges.394041  One review found obese mothers are less likely to breastfeed and calls for more research into the reasons behind this.42

Do I need to take breastfeeding vitamins or supplements?

In most cases if you are eating a healthy diet you will be getting all the vitamins and minerals you need and your body will automatically add these to your breast milk in just the right amounts. Abe et al, 2016 43 have reviewed the effects of vitamin supplements and found there was insufficient evidence to make a recommendation and that further studies were needed. In the UK the National Health Service (NHS) recommends taking vitamin D supplements but says other vitamins and minerals can be obtained by a varied and balanced diet.44 However be aware that certain vitamin or mineral deficiencies can creep in with some diets and lifestyles:

Vitamin D

Vitamin D is made in the body following exposure of the skin to sunlight and a little comes from our diet. Some people are deficient in this vitamin due to lack of sunlight and it is hard to get enough from diet alone. Check our article Vitamin D and Breastfeeding for current recommendations on supplements for you and your baby.

Vitamin B12

Vegan diets and some strict vegetarian diets may not have enough natural sources of vitamin B12 (cobalamin). Vitamin B12 deficiency is also a possibility for mothers who have had surgery to reduce the size of their stomachs (bariatric or gastric-bypass surgery) or mothers who have digestion or absorption issues eg Crohn’s disease (Marasco and West, 2020 p 90). Marasco and West say that some medications can also affect B12 levels, and mention metformin, hydrocortisone and the antibiotic amoxicillin. Mothers at risk of low B12 may need to check their vitamin status or take supplements so that their babies will be sure to get enough vitamin B12 via their breast milk.

  • Mothers with a B12 deficiency may not have any symptoms but some may have problems with making enough milk (Marasco and West, 2020 p 90).
  • Babies deficient in vitamin B12 may be pale, lethargic and not interested in feeding which could lead to slow weight gain (failure to thrive). They may have a developmental delay, low muscle tone (hypotonia), or reversal of normal development eg losing the ability to sit up. 45 46  Deficiency of B12 may lead to a type of anaemia requiring urgent treatment.47


Iodine is a trace element found in sea food, seaweed, dairy produce, eggs and some plant foods. Iodine helps to make thyroid hormones which are important for making milk. Levels of iodine in plants vary, depending how much iodine is available in the soil.48 As some diets can be low in iodine, and breastfeeding mothers have a higher requirement, some countries recommend routine iodine supplementation.4950 Requirements for iodine in pregnancy and lactation are high and if a mother is deficient this could affect thyroid gland function and milk supply (Marasco and West, 2020). Smoking can reduce iodine levels in breast milk even further 51 increasing the risk of iodine deficiency-induced brain damage.

In the UK the Association of UK Dietitians has produced a fact sheet on iodine discussing when supplements are needed during pregnancy and breastfeeding and the levels recommended. Consult with your health care professional whether iodine supplements are recommended where you live.


For further information about iron levels in breast milk and in which situations your baby’s iron levels might be low, see Iron in Breast Milk. Taking supplements won’t increase iron levels in breast milk but a low iron status for mother could be linked with low milk supply.

Further reading

Making More Milk (Marsco and West, 2020) discusses other minerals that are important for lactation and milk supply e.g. Zinc and Calcium and discusses the role of sufficient dietary fibre, overall calories, protein content and antioxidants.

display of vegetables in market
A breastfeeding mother can eat and drink most things and there aren’t any specific foods to avoid Photo by Somi Jaiswal on Unsplash


There are no strict rules to follow for a breastfeeding diet and there are no particular foods to avoid during breastfeeding. Breast milk is made to order by the breast using the mother’s diet and her body stores. Maternal diet can influence breast milk quantity and quality in subtle ways if certain nutrients are deficient. New research into the role of essential fatty acids in breast milk highlights the value of healthy fats in the maternal diet for both mother and baby. Mothers could check with their health care professionals if they have any concerns that their diet may be low in any specific vitamins or nutrients. Occasionally a baby will react to something in his mother’s diet and she can then avoid that food for a while.