How your diet affects your breastmilk


You are what you eat!

When you are breastfeeding you can generally enjoy all the foods that you would usually eat. Occasionally though, something you eat can niggle your baby. If this happens, simply leave that food out of your diet for a week or so and then try it again.


The great thing about breastmilk is that the flavour changes, depending on what you eat. This can actually help with weaning later on too, as your baby will have had a little bit of variety in their first few months.

Foods you might want to avoid eating

Occasionally, your baby might react to something you’ve eaten. Every baby is different, so see how yours responds after feeding. But here are a few foods that may affect your baby:


  • Caffeine – it can wake you up if you’re feeling tired out, but it can mean your baby has difficulty sleeping, too so try to limit it, especially in the early days.
  • Certain fish - a maximum of 2 portions of oily fish per week or one portion of shark, swordfish or marlin is appropriate due to possible build-up of mercury.

Note: Peanuts - It is now considered safe to eat peanuts while breastfeeding even if you have a family history of allergy.

Is your baby allergic to something you’ve eaten?

If your baby has an upset stomach or rash after feeding, they may be allergic to something you’ve eaten. Cows’ milk, nuts, wheat, fish and eggs are just some foods which can cause an allergic reaction. If this happens, it is best to speak to your healthcare professional. Many mums find that keeping a food diary makes it much easier to track how their baby responds after each feed.

Drinking alcohol and breastfeeding

It’s best to avoid alcohol when you are breastfeeding. If you do drink a small amount (1 or 2 units), make sure you have enough expressed breastmilk to last for 2 - 3 hours, while your body deals with the alcohol in your system. You may need to express some excess milk during that time to make sure that your breasts do not become engorged.


One unit of alcohol is:


  • ½ pint of ordinary strength beer, lager, or cider
  • ¼ pint of strong beer or lager
  • ½ a standard glass of wine
  • 1 single measure of spirits
  • 1 small glass of sherry

Drinking plenty of fluids (about 12 glasses of water a day) will help stop you dehydrating and help keep a reliable milk supply for your baby.

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