Post-partum Protein
As part of my research into post-partum recommendations for clients, I was looking into the guidelines for protein recommendations specifically in breastfeeding women.
The NHS and British Nutrition Foundation recommend 0.75g protein per kg of body weight for the average adult, for lactating post-partum women they generously add an extra 11g/day up to 6 months, and 8g/day there after (here).
From a holistic, functional perspective these, recommendations are far too low.
Purposes of protein post partum
Tissue repair & wound healing
The amino acids that make up proteins are the building blocks of the body. They are required, in all the variety, to grow and repair muscle and other body tissue. After pregnancy and birth our uterus shrinks down over six weeks, the site of the placenta attachment heals, vaginal grazes and tears repair, c-sections incisions heal and the pelvic floor and abdominal wall shorten again following stretching. All of this healing requires protein.
Breastmilk
Breastmilk isn’t just milk. It is living nectar for your baby. It contains a combination of whey and casein which alters in ratio over time depending on your baby’s needs. Some specific proteins include:IgA which coats the respiratory and digestive tracts to protect against pathogensAlpha-lactalbumin which supports digestion and gut health
Lysozyme an enzyme that breaks down pathogenic bacteria’s cell walls
Protein promotes prolactin, our milk producing hormone. Your biological make up is to keep baby alive at no matter what cost, which means if your protein intake does not meet the needs of your breastmilk composition it will leach it from your reserves. This will have a knock affect on your own muscle mass, energy and immunity.
Energy & hormone regulation
Growing, birthing and raising children is a high energy demand activity. Feelings of fatigue, brain fog, ‘touched out’ can all be signs of a mother whose energy expenditure is higher than her intake. Carbohydrate intake will naturally, and necessarily, increase. When blood sugar spikes and crashes, on top of lack of sleep, cortisol is released. High protein intake mitigates the carb rollercoaster, reducing the stress response and its negative impact. Protein also supports thyroid function to regulate metabolism, aka energy production.
How current recommendations are set
The baseline adult recommendation stems from nitrogen balance studies designed only to identify the minimum needed to avoid deficiency. For breastfeeding women specifically, the UK recommendation wasn't even based on direct measurement in real women. Instead, scientists estimated it mathematically. They looked at the average protein content of breastmilk, multiplied it by how much milk a woman typically produces in a day, and used that to calculate how much protein she must need to eat. This is called the factorial method. The problem is that this calculation assumes the body converts dietary protein into breastmilk at a particular efficiency, like assuming a car converts fuel to miles at a fixed rate regardless of the terrain. Research suggests that in lactating women, that conversion is actually far less efficient than assumed. The calculation uses an efficiency rate of 0.7. Studies have found it may be as low as 0.25 in breastfeeding women. In practical terms, that means the recommendation could be significantly underestimating how much protein a mother actually needs to produce that milk, before we've even factored in everything else her body is doing.
A better method exists
The Indicator Amino Acid Oxidation technique (IAAO) works by measuring how the body processes a specific amino acid as protein intake increases. As intake rises to meet the body's true requirement, oxidation of that amino acid drops and plateau, and that breakpoint identifies the actual need. It is more sensitive, more physiologically meaningful, and consistently produces higher requirement estimates than nitrogen balance or factorial methods. Critically, it measures what is actually happening in the body rather than estimating it from milk composition averages and assumed efficiency ratios.
Recent research breakdown
The most recent research we have comes from a 2020 study by Rasmussen and colleagues, which used the IAAO method to directly measure protein requirements in exclusively breastfeeding women between three and six months postpartum. It found that mothers in this group needed between 1.7 and 1.9g of protein per kilogram of bodyweight per day, significantly higher than current guidelines.
The strength of this study lies in its method. IAAO is considered more accurate and more physiologically relevant than nitrogen balance, and critically, this was the first time it had been applied to this specific population. It gives us actual data on breastfeeding women, rather than figures extrapolated from studies on men or derived from theoretical calculations about the energy cost of milk production.
The limitation is the sample size. Eleven participants is small, and from a research standards perspective, that makes it difficult to draw sweeping conclusions or use it as the sole basis for updating population-level guidelines. But a small study is not the same as a weak study. The IAAO method is designed to be applied at the individual level, and the findings are consistent with what we would expect physiologically given the demands of lactation and postpartum recovery.
The real issue isn't that this study is insufficient, it's that it remains the only one. Post-partum health research is notoriously under funded and under researched. Women are finding their way through the most depleting time of one’s life without accurate, up to date guidance.
Tips to increase your protein intake
Start off the day on a high! Make sure you are hitting protein intake right off. I’m currently in weaning land so this means ALOT of prep; I have prepped chia pots I add collagen to and boil batches of eggs (they survive in the fridge a surprisingly long time)
Aim for four meals a day, roughly three to four hours apart, with around 30 grams of protein at each sitting. That gets you to approximately 120 grams per day which for most postpartum women sits within the range suggested by the most current research.
Prep. Prep prep prep. Don’t over complicate it though. Soups and stews are your best friends. Chuck veg, meat, herbs and salt into a pot in your oven or slow cooker and get on with your day.
Ask for help. If you’re reading this thinking ‘yeah right, sometimes I forget to eat altogether’ that is a sign you need more support, not more willpower and there is no nobility in running on empty. Putting a stew in the oven, baking some chicken and salmon fillets and prepping chia pots is a 45 min task, max. Ask a partner, friend or family member to support you. You could even give them the recipes.
Animal meats first for their deeply nourishing properties. Good quality collagen and protein powder second to top up protein content and easy snacks.
The guidance exists. It just isn't good enough and until the research catches up, you deserve better than recommendations built on estimates, averages, and data that was never collected with you in mind. Your body grew a human. It birthed that human. It is now feeding, healing, and sustaining life simultaneously. That is not a moment to settle for the minimum.
Start where you can. One protein-rich meal. A batch of boiled eggs in the fridge. A slow cooker on before the school run. Small, consistent changes compound and your recovery will reflect them.
If you want support working out what your body specifically needs right now, I work with postpartum women in clinic to build a nutrition plan that actually meets the demands of this season. You can book a discovery call here.
