What to Eat While Breastfeeding: Practical, Evidence-Based Advice on Nutrients, Hydration and Foods to Limit
If you are breastfeeding and confused about what on earth you are “allowed” to eat, you are not alone. Between well‑meaning relatives, random Instagram posts and old-fashioned advice, it can feel as if every food on your plate is somehow dangerous.
Here is the truth that often gets buried under all that noise: most breastfeeding mothers do not need a restrictive diet.
Your body is smart. It knows how to make breast milk from a wide variety of foods. You do not have to cut out dairy just in case, or eat plain boiled chicken for months, or panic every time you fancy a curry.
This article will walk you through what to eat while breastfeeding, what to actually limit, and which myths you can safely ignore. Evidence-based, guilt-free, and realistic for life in the UK with a baby who does not care if you have had lunch yet.
The biggest myth: you do NOT need a restrictive diet while breastfeeding
You may have heard at least one of these:
- “No dairy at all if you are breastfeeding.”
- “Garlic makes your baby gassy.”
- “You must avoid spicy food and cabbage.”
- “Beans and lentils cause colic in breastfed babies.”
Most of this is myth.
Your milk is quite stable
Human milk composition is much more stable than people think. According to the NHS and multiple European breastfeeding organisations, a mother’s diet affects only some components of breast milk, and usually not in dramatic ways.
Your body prioritises your baby. It will pull nutrients from your own stores if needed and still produce milk that is right for your child. That does not mean your own diet does not matter - it does, for your energy, mood and long-term health. But it rarely requires extreme restrictions.
Do you need to avoid dairy, garlic, spicy food or cabbage “just in case”?
In most cases, no.
-
Can I eat dairy while breastfeeding?
Yes, unless your baby has clear signs of cow’s milk protein allergy (we will cover that later). Yoghurt, cheese, milk in your tea, all fine for most mothers. -
Spicy food and breastfeeding
In many cultures, mothers eat spicy food daily while breastfeeding and babies grow and feed happily. Some research has shown that flavours from garlic and spices can even pass into breast milk and may help babies accept family foods more easily later. Indian, Mexican, Thai mums are not living on plain toast for a year, and neither do you need to. -
Garlic and breastfeeding
Garlic can slightly change the smell and taste of your milk. Studies from Germany and elsewhere actually found that some babies suckled longer after mums had eaten garlic. So much for “they will refuse the breast”. -
Cabbage, beans and foods that cause gas in breastfed babies
The gas you get as an adult is produced in your gut, not in your milk. It does not travel directly into breast milk. Some babies are sensitive to certain proteins or sugars, but for most, their fussiness is not linked to you having broccoli.
You only need to remove foods if you see a clear, repeated pattern of your baby reacting (and even then, it is usually temporary and targeted, not a blanket ban on half the supermarket).
What a balanced breastfeeding diet really looks like
Instead of thinking “diet while breastfeeding” as a list of forbidden foods, think of it as normal healthy eating with a bit more flexibility for hunger and tiredness.
The basics
Aim for:
-
Plenty of plants
Fruit, vegetables, beans, lentils, whole grains. Frozen and tinned (in water) are fine. This is real life. -
Good protein sources
Eggs, poultry, fish (including oily fish), lean red meat, Greek yoghurt, cheese, tofu, beans, lentils, nuts and seeds. -
Healthy fats
Olive oil, rapeseed oil, avocado, nuts, seeds, oily fish. -
Carbohydrates for energy
Wholemeal bread, porridge oats, brown rice, pasta, potatoes, sweet potatoes. White bread and rice are not banned either, just balance them.
Perfection is impossible with a newborn. A cheese sandwich and a banana eaten one‑handed while feeding still counts as a decent meal. Your breastfeeding nutrition does not need to look Instagram‑ready.
How many calories while breastfeeding?
Your body uses energy to make milk. On average, breastfeeding uses about 400 to 500 extra kcal per day in the first six months, according to NICE guidance and UK dietetic recommendations.
That does not mean you must count calories, just that:
- You will probably feel hungrier. Listen to that.
- This is not usually the ideal time for an extreme weight-loss diet.
- A slight, gradual weight loss is normal, but feeling faint, dizzy or constantly exhausted can be a sign you are not eating enough.
A rough guide:
- If your weight was stable and healthy before pregnancy, you might need about an extra 2 small snacks or one bigger meal’s worth of energy spread through the day.
- Examples:
- A bowl of porridge with milk and berries.
- Wholemeal toast with peanut butter.
- Greek yoghurt with fruit and a handful of nuts.
If you had a higher weight before pregnancy, your body may use some of its stored fat for milk production, so you may not need the full 500 kcal every day. The key is to eat to appetite and not intentionally restrict to the point of feeling unwell.
Hydration: how much water while breastfeeding?
You do not need to drink gallons, or force water until your pee is completely clear. That old advice is outdated.
General guide:
Around 2 to 2.5 litres of fluids per day works for many breastfeeding mothers in the UK climate. That includes water, milk, tea, coffee and fluids in food such as soups and fruit.
More useful than counting glasses is this:
- Drink to thirst.
- Keep a drink near every feeding spot: sofa, bed, favourite armchair.
- Aim for pale yellow urine.
- If you are very active, it is hot, or you are feeding twins, you may need more.
Plain water is great, but you can also include:
- Herbal teas (watch ingredients if they are marketed as “detox” or “slimming”).
- Milk.
- Weak squash.
- Tea and coffee within your caffeine limit (we will come to that).
Feeling dry-mouthed, light-headed or having headaches can be signs you need more fluids.
Essential nutrients while breastfeeding
Your body is doing serious work. A good breastfeeding diet pays special attention to a few key nutrients.
Iron
Pregnancy and birth can lower iron stores, and fatigue from low iron can feel very similar to “new mum tired”.
Good sources:
- Lean red meat.
- Dark meat poultry.
- Beans and lentils.
- Dark green leafy veg like spinach, kale, spring greens.
- Iron-fortified breakfast cereals.
Pair plant sources with vitamin C (like peppers, oranges, strawberries) to help absorption. If you had significant blood loss at birth or were anaemic in pregnancy, your GP or midwife may recommend a supplement.
Calcium
You need calcium for bones and teeth, and your body will draw on your bones if your intake is low.
Aim for about 1,000 mg per day of calcium from:
- Milk, yoghurt, cheese.
- Calcium-fortified plant milks (check the label).
- Tinned fish with soft bones, like sardines.
- Tofu set with calcium.
- Some leafy greens like kale and pak choi.
Omega‑3 while breastfeeding
Omega‑3 fatty acids, especially DHA, support your baby’s brain and eye development and your own mental health.
Good sources:
- Oily fish such as salmon, mackerel, sardines, herring, trout.
- Omega‑3 enriched eggs.
- Walnuts, chia seeds, flaxseeds (these provide ALA, which your body converts less efficiently to DHA but still helps).
In the UK, the current advice is:
- Eat at least one portion of oily fish a week, but:
- Limit oily fish to two portions a week if you are breastfeeding, because of pollutants that can build up.
- Avoid shark, marlin and swordfish.
If you do not eat fish, consider an algae-based omega‑3 supplement. Many UK dietitians recommend this for vegetarian or vegan mothers.
Vitamin D breastfeeding
Vitamin D affects bone health, immune function and mood. In the UK, sunlight is not strong enough for good vitamin D production all year.
Current UK guidance suggests:
- Adults, including breastfeeding mums, usually benefit from a daily supplement of 10 micrograms (400 IU) vitamin D, especially in autumn and winter.
- Some women are at higher risk of low vitamin D (for example, if you have darker skin, cover most of your skin outside, or rarely go outdoors).
Talk to your GP or health visitor if you are unsure, or check the NHS guidance on vitamin D.
Iodine during breastfeeding
Iodine supports your baby’s brain development and your thyroid function. Many people in the UK do not realise how important it is.
Sources include:
- Dairy products such as milk and yoghurt.
- White fish.
- Eggs.
- Some seaweeds, but be careful: large amounts of kelp or kombu can contain too much iodine.
If you are vegan or avoid dairy and fish, speak with a dietitian or GP about whether you need an iodine supplement suitable for breastfeeding.
What to actually limit in a breastfeeding diet
So far we have talked about what you can eat. There are a few things where caution genuinely matters.
Caffeine and breastfeeding
You do not have to give up coffee. Good news.
Caffeine does pass into breast milk but generally in small amounts. Most guidelines, including the NHS, suggest keeping to around 200 to 300 mg of caffeine per day while breastfeeding.
Roughly, that looks like:
- 1 mug of filter coffee (about 140 mg) + 1 cup of tea (about 75 mg), or
- 2 cups of instant coffee, or
- 3 to 4 cups of tea.
Remember:
- Energy drinks can contain a lot of caffeine.
- Dark chocolate also has small amounts.
If your baby seems unusually jittery, very wakeful or fussy and you are drinking a lot of caffeine, try cutting back and see whether it helps.
Alcohol and breastfeeding
There is no completely safe level of alcohol for a baby, but the way alcohol enters and leaves breast milk is often misunderstood.
Key points:
- Alcohol levels in your milk are similar to levels in your blood.
- It peaks about 30 to 60 minutes after you drink (or 60 to 90 minutes with food).
- Your body clears it gradually. “Pumping and dumping” does not make it disappear faster; only time does.
Health organisations in the UK generally advise either avoiding alcohol while breastfeeding or keeping it to occasional, small amounts, timed carefully.
If you do choose to drink:
- Plan feeds:
- Feed or express just before drinking.
- Leave at least 2 to 3 hours per unit of alcohol before the next feed direct from the breast.
- One UK unit is about:
- Half a pint of normal-strength beer, or
- A small (125 ml) glass of wine, or
- A single measure of spirits.
If your breasts become uncomfortably full while you wait for alcohol to clear, you can express and discard the milk to stay comfortable. That is where “pump and dump” has a role, but it does not reduce the alcohol percentage itself.
If alcohol is a sensitive subject for you or you are finding it hard to cut back, talk to your GP or health visitor confidentially.
Foods that may cause fussiness in some babies
Here is where individual variation comes in.
Some babies do seem sensitive to particular foods in their mother’s breastfeeding diet. Common suspects include:
- Strongly spiced foods.
- Cabbage, broccoli, onions.
- Chocolate.
- Citrus fruits.
- Tomatoes.
But, and this is key, this is not universal. For every mother who swears that onion made her baby miserable, there is another whose baby slept happily after a big bowl of chilli.
A sensible approach:
- Do not preemptively cut all these foods.
- If your baby is very fussy, has a lot of wind or seems uncomfortable, keep a simple food and symptom diary for a week or two.
- Look for patterns:
- Does fussiness appear within a few hours of you eating a specific food, on several separate days?
- If a clear link appears, try:
- Removing that food for 1 to 2 weeks.
- Reintroducing it once and watching.
If the symptoms go away and then return clearly when you reintroduce the food, you might have found a trigger. Often, this sensitivity improves as your baby’s gut matures.
If you are removing entire food groups or more than one major food (like dairy and soy), please get support from a dietitian or GP so your own nutrition stays solid.
Real food allergens to watch for in your baby
Most babies are not affected by what their mums eat apart from normal variations in wind and mood. A small number, though, have genuine allergies or intolerances.
The most common concern is cow’s milk protein allergy (CMPA).
Cow’s milk protein through breast milk
Cow’s milk protein from your diet can pass into breast milk in tiny amounts. For babies with CMPA, even that can cause symptoms.
Things that can signal a problem:
- Blood or mucus in your baby’s stool.
- Persistent, severe eczema that does not respond to usual treatments.
- Very distressed crying, back-arching, and vomiting after feeds.
- Poor weight gain.
- Frequent wheeze or breathing issues without another clear cause.
This is very different from a bit of wind or random fussiness.
If you notice symptoms like blood in stools or severe eczema:
- Do not just cut everything out on your own.
- See your GP or paediatrician as soon as you can.
- Ask specifically about potential cow’s milk protein allergy while breastfeeding.
Under medical guidance, you may be advised to:
- Remove all obvious and hidden cow’s milk from your diet for a period (often 2 to 4 weeks).
- Have support from a dietitian to make sure your diet while breastfeeding still gives you enough protein, calcium and calories.
- Reintroduce dairy in a controlled way to confirm the diagnosis.
Other allergens like soy, eggs or nuts can also appear in breast milk, but reactions to them via breast milk are less common. Again, do not self-diagnose multiple allergies without support, or you risk unnecessary restriction and nutrient gaps.
Supplements during breastfeeding: what helps and what is optional
Vitamin D for baby
In the UK, the NHS recommends that:
- Breastfed babies from birth to 1 year should have a daily supplement of 8.5 to 10 micrograms (340 to 400 IU) vitamin D.
- The only exception is if your baby is having more than 500 ml of infant formula a day, because formula is already fortified.
Even if you take vitamin D, your milk typically does not contain enough to meet your baby’s full needs, unless you are on high-dose prescriptions guided by a doctor. So those daily baby drops matter.
Omega‑3 for mum
If you eat oily fish once or twice a week, your omega‑3 intake is likely reasonable. If not, especially if you are vegetarian or vegan, an omega‑3 supplement can be useful.
Look for:
- A supplement that includes DHA, and preferably EPA as well.
- If you are vegetarian or vegan, an algae-based DHA supplement instead of fish oil.
Other supplements:
- A general breastfeeding or postnatal multivitamin is sometimes helpful, especially if your diet is patchy because you are exhausted.
- Iron should only be taken as a supplement if you are known to be low or at risk, since too much iron is not harmless.
If you are unsure what you need, talk to your GP, midwife or a registered dietitian. Avoid random high-dose supplements bought online that promise miracle milk supply.
Let go of guilt: your breastfeeding diet does not need to be perfect
New motherhood in the UK these days comes with pressure from every angle: feed this way, bounce back that way, never eat this, always eat that. It is exhausting.
Here is a different message:
- You can eat dairy, garlic, spicy food and cabbage while breastfeeding, unless your baby shows a clear, specific problem.
- You do not need a rigid list of foods to avoid while breastfeeding.
- Most babies cope just fine with a mother who eats a normal, varied diet.
- Your own health matters as much as the milk you produce.
So:
- Eat regularly.
- Drink to thirst.
- Include iron, calcium, omega‑3, vitamin D and iodine where you can.
- Limit caffeine and alcohol sensibly.
- Watch your baby, not random advice on the internet.
And if some days your “breastfeeding nutrition” is tea, toast and biscuits? You are still a good mum. Feed yourself as kindly as you feed your baby, and your body will do the rest.
We as the developers of the Erby app disclaim any liability for any decisions you make based on this information, which is provided for general informational purposes only and is not a substitute for personal medical advice.
