What to eat when breastfeeding: nutrition, calories and foods to limit

Breastfeeding · Updated July 2026 · All articles

Most of the rules people worry about when it comes to breastfeeding and food turn out to be myths. The list of things you genuinely need to avoid is short, and the basic nutritional requirements are not wildly different from what any healthy adult needs. What matters most is eating enough, staying reasonably nourished, and knowing which specific things are actually worth being careful about.

How many extra calories do you need?

Producing breast milk uses energy: roughly 500 kilocalories per day above your normal requirements. However, your body uses fat stores built up during pregnancy to contribute to this, meaning the amount you actually need to eat above your usual intake is closer to 300 to 400 kilocalories per day in the early months, assuming a typical postpartum body composition.

Rather than counting calories precisely, focus on eating regular, nourishing meals and not skipping meals through busyness. Many breastfeeding parents find they are genuinely much hungrier than usual, which is the body's natural signal to eat more. This is a helpful instinct: listen to it. Undereating while breastfeeding is a more common problem than overeating, and going without food for long stretches affects your energy and mood much more than it typically affects milk supply.

Key nutrients to prioritise

Iodine is one of the most critical nutrients during breastfeeding and one that many people in the UK are mildly deficient in. Iodine is essential for your baby's thyroid function and brain development, and the amount in your milk depends directly on how much you consume. Good dietary sources include dairy products, eggs, fish, and some seaweeds (though be cautious with kelp and other seaweeds as they can contain unpredictably high amounts). If you do not eat dairy or fish, an iodine supplement is worth considering.

Calcium needs remain elevated during breastfeeding, though your body becomes more efficient at absorbing it. Dairy, fortified plant milks, sardines with bones, broccoli, kale, and fortified foods all contribute. Most people who eat a varied diet get enough calcium, but if you avoid dairy entirely without replacing it, it is worth reviewing your intake.

Vitamin D is the supplement most strongly recommended for breastfeeding parents in the UK. NHS guidance advises taking 10 micrograms (400 IU) daily, as breast milk tends to be low in vitamin D regardless of what you eat. Your baby may also be advised to receive vitamin D drops, especially if they are exclusively breastfed. Ask your health visitor for current guidance.

Omega-3 fatty acids, particularly DHA, are important for your baby's brain and eye development. Oily fish (salmon, mackerel, sardines, trout) two to three times a week is the most straightforward source. If you do not eat fish, an algae-based DHA supplement provides the same form of omega-3 that fish themselves obtain from algae. Flaxseed and walnuts provide a different form (ALA) that the body can partially convert, but the conversion rate is low.

Foods and drinks to limit

Alcohol is the most important substance to limit. It passes into breast milk at the same concentration as it is in your blood. The NHS advises that if you do drink alcohol while breastfeeding, you should wait at least two to three hours per unit before nursing. One small glass of wine (around 1.5 units) takes about three hours to clear fully. Expressing milk before drinking and having expressed milk ready for the next feed is a practical option. The safest choice is not to drink at all, particularly in the first three months.

Caffeine is safe in moderation. The generally cited limit is 200mg per day, about the same as the limit during pregnancy. This is roughly equivalent to two cups of filter coffee or four cups of tea. Excessive caffeine can cause irritability and poor sleep in some babies, particularly newborns whose systems are less efficient at metabolising it. If your baby is particularly unsettled and sleeps poorly, experimenting with reducing caffeine is worth trying.

High-mercury fish should be limited. Shark, swordfish, marlin, and king mackerel are the main ones to avoid. These fish accumulate mercury through the food chain, and high mercury levels can affect a baby's developing nervous system. Oily fish lower in mercury (salmon, trout, sardines, herring, mackerel other than king mackerel) are safe and nutritious in normal portions of two to three times a week.

Myths about breastfeeding and diet

You do not need to avoid garlic, onions, dairy, spicy food, gassy vegetables, or any other food as a standard precaution. These are common restrictions passed down through generations and cultures, but there is no consistent evidence that a breastfeeding parent's normal dietary choices cause colic, wind, or distress in their baby. If you notice a strong pattern, such as your baby being very unsettled every time you eat a particular food, you can try removing that food for a couple of weeks to observe whether it makes a difference. But eliminating food groups unnecessarily risks nutritional gaps and is not justified by the evidence.

Cultural traditions around postpartum diet, such as specific warming foods, galactagogue foods, and restrictions on cold or raw foods, vary widely and many have their roots in traditional wisdom around postpartum recovery. If these practices are meaningful to you and your family, following them is unlikely to cause harm and may provide comfort and community. The important thing is not to add nutritional restriction on top of cultural restriction without thinking about what you might be missing.

Does your diet affect milk flavour?

Yes, mildly. Strongly flavoured foods can subtly alter the taste of breast milk. Garlic and curry, in particular, have been noted to change milk flavour in research studies. Interestingly, this appears to be a benefit rather than a problem: babies whose parents ate more varied diets during breastfeeding showed more acceptance of those flavours when they were introduced to solid foods. Your milk is gradually familiarising your baby with the tastes of your household's food culture, which is a lovely thing.

Hydration

You will probably find you are thirstier than usual when breastfeeding, which is a useful natural reminder to drink more. Keep a water bottle in your usual feeding spot. Drinking to thirst is a perfectly adequate guide for most people. You do not need to force large quantities of extra fluid: drinking more water than your body requests does not increase milk supply, and some people find it bloating and uncomfortable.

Any fluid counts toward hydration, not just water. Tea, coffee (within the caffeine limit), milk, juice, and soup all contribute. Broth-based soups and warm drinks also tie into many traditional postpartum recovery practices and can be genuinely comforting alongside their hydration benefit.

Supplements worth taking

Vitamin D (10 micrograms daily) is the clearest recommendation. An iodine supplement is advisable if your diet is low in dairy and fish. DHA/omega-3 is worth considering if you do not eat oily fish regularly. A postnatal multivitamin that covers these bases is a practical and convenient option if you would rather not manage multiple separate supplements. Check the label for iodine, as not all postnatal multivitamins include it. Your GP or health visitor can advise on what is right for your situation.

Frequently asked questions

How many extra calories do I need when breastfeeding?

Most breastfeeding parents need roughly 500 extra calories a day above their usual intake, though this varies with how much you are nursing. Your body also draws on fat stores laid down during pregnancy to contribute to milk production, so the real additional food intake needed is closer to 300 to 400 calories for most people. Focus on nutrient-dense choices rather than trying to hit an exact number.

Do I need to avoid certain foods when breastfeeding?

There is no standard list of foods to avoid. Most things you eat are safe in moderation. The main categories to be mindful of are: alcohol (if you drink, wait around two hours per unit before nursing); caffeine (safe up to around 200mg per day, about two cups of coffee); and high-mercury fish such as shark, swordfish, and marlin (limit to one portion per week). You do not need to cut out garlic, dairy, spicy food, or any other food unless your specific baby reacts to something.

Which supplements should I take when breastfeeding?

Vitamin D is the one most clearly recommended. NHS guidance advises all breastfeeding parents take 10 micrograms of vitamin D daily. Iodine is important for your baby's brain development and many breastfeeding parents in the UK do not get enough through diet alone. Omega-3 (particularly DHA) is worth considering if you do not eat oily fish regularly. A postnatal multivitamin covering these bases is a practical option if you would rather not manage separate supplements.

Is it safe to drink alcohol when breastfeeding?

Alcohol passes into breast milk at similar concentrations to blood alcohol. The safest approach is not to drink at all, particularly in the first months. If you do drink, the generally cited guideline is to wait around two to three hours per unit of alcohol before nursing, to allow it to clear from your blood and therefore your milk. Expressing before drinking (and having a bottle ready) or timing a drink immediately after a feed can reduce exposure to your baby.

Does what I eat affect the taste of my milk?

Yes, mildly. Strong-flavoured foods such as garlic, curry, and strong vegetables can give milk a slightly different flavour. Research actually suggests this may be beneficial, gradually introducing babies to the tastes of family foods before weaning. Most babies do not object to these subtle variations and it is rarely a reason to restrict your diet. If you suspect a specific food is causing your baby distress, you can try removing it for a couple of weeks to see if it makes a difference, but blanket dietary restriction is not necessary or recommended.

Does hydration affect milk supply?

Staying well hydrated is important for your overall wellbeing and energy levels. However, drinking extra fluid beyond your normal thirst level does not increase milk volume. Dehydration can affect supply if it is severe, but drinking two litres of water a day when you are not thirsty will not make more milk. Drink to thirst, which may mean drinking more than usual, and keep a water bottle nearby during feeds as a practical reminder.

This article is for general information only. Always consult your midwife, health visitor, GP, or a registered lactation consultant for advice about your specific situation.