How many calories do you need for breastfeeding?

Aug 31, 2022
Sheridan Skye

How many calories do you need for breastfeeding?

Our Head of Nutrition, Sheridan Skye answers this question!


If I had a dollar for every time someone asked me this question; I’d probably have, well, a few thousand dollars! 

Yes, you do need more calories when you are breastfeeding. How many? Well, that’s the tricky part. It’s a nuanced topic; there’s no doubt about it, and it’s why I dedicated an entire three-part series to answer this very question in our upcoming postnatal series (shameless plug). But I don’t want to leave you hanging, and I hope that this blog gives you some little nuggets you can walk away with and implement right away.

You’ll hear several different values when it comes to this question. Some say 200, some say 300, and some say 800, which is a big difference when you stop to think about it!

Butte and King published a brilliant paper on the energy requirements during breastfeeding. They concluded that women require up to 625 extra calories per day in the first five months to support exclusive breastfeeding. 

So does that mean ALL women should eat an additional 625 calories per day for the first five months? 

Well, not exactly! This number does vary a lot amongst women. I mean, imagine if your energy requirements were + 100 calories and here you are going straight to + 600 calories (whoops). 

Here are some things you need to consider: 

  • Are you exclusively breastfeeding (aka, no other food such as solids or formula are being offered)? If yes, your energy needs will be slightly higher. If not, they are likely lower. 
  • How old is your baby? Energy requirements tend to be highest in the first five months of feeding, which usually coincides with the introduction of solids. When your baby becomes well established on solids, they will begin to take in less milk. So a baby who is five weeks old compared to a baby who is nine months old will need different volumes of milk. Mama’s who choose to breastfeed beyond 12 months will require even less energy for their milk supply because their (now toddler) will be taking in even less milk).
  • Are you feeding multiples or tandem feeding? Self-explanatory right – more babies = higher energy demands. 

Is dieting safe during breastfeeding? 

Short answer, yes. When energy is restricted, the long answer is often the mother’s health is at greater risk over the potential decrease of her milk supply. And that is because your body will prioritise your baby’s needs over you! (Welcome to motherhood. No, I’m joking. But only a little. 

Why is this? 

Losing fat requires you to restrict calories (energy), and restricting calories (energy) means limiting micronutrients. Since you are already depleted of many essential micronutrients after birth (iodine, vitamin D, EPA/DHA, to name a few), this puts you (mum) at greater risk of micronutrient deficiencies.

But all in all, a slow and steady approach to fat loss (around 0.5-1kg per week) seems to be safe for milk production. So, if you decide to diet, make sure you are prioritising your fruits and veggies (your pelvic floor will also love the added fibre, constipation isn’t great for a weak pelvic floor).

How do you best determine your unique energy requirements? 

You can estimate your maintenance calories by using a simple TDEE calculator ( is an example) and then add some depending on how many months postpartum you are. 

Of course, you will need to adapt a little trial and error here because it won’t be perfect. Or, if you’re like me and you’d rather do it right with the expert guidance of a qualified postnatal nutritionist, we will show you ‘how to’ in our upcoming postnatal series. 

Yours in health,

Sheridan Skye

Head of Nutrition