How Much Protein Do Women Actually Need?

When we added a short quiz to the Kultra website, I expected most people to tell us about a specific health worry, and plenty of them do, however one of the goals that keeps being chosen has nothing to do with a condition at all. It's simply "I want to understand how much protein I actually need as a woman", and honestly, I think that's one of the most sensible questions anyone can ask, because the answers out there are either written for six-foot men who lift every day, or they're so vague that they don't really help. It's also a question I had to answer properly for myself when I started Kultra, because I couldn't put a protein powder into the world without understanding where it genuinely fits into a woman's day.

So I did what I always do. I went to the research, and what I found was reassuring in some ways and surprising in others. If you've ever felt confused about the numbers, you're definitely not alone, and it isn't a personal failing... most of us were never taught any of this. I'm not a doctor or a dietitian, so please treat this as what I've learned rather than personal advice, and check with your GP or a registered dietitian about your own situation.

Where the official number comes from

In the UK, the reference nutrient intake for protein is 0.75g per kilogram of body weight per day for adults [1]. It's set to cover the needs of almost everyone in the healthy population, which is a lovely, safe starting point, but it's worth knowing that it was designed as a baseline to avoid deficiency, rather than as a target for building or holding on to muscle as we get older.

To make that real, for a woman who weighs 70kg, 0.75g per kilo works out at about 53g of protein a day. However, researchers looking at healthy ageing have suggested that older adults may benefit from more than that, and the PROT-AGE study group recommended 1.0 to 1.2g per kilo for people over 65 [2], which for the same woman would be roughly 70 to 84g a day.

A day of protein, for a 70kg woman

Grams of protein per day

UK reference intake (0.75g per kg)about 53g

PROT-AGE suggestion, over 65s (1.0 to 1.2g per kg)70 to 84g

One serving of Kultra (two level scoops)26g

What changes through your 20s, 30s and 40s

I used to think of protein as one number that stayed the same for life, but the more I read, the more I realised that what our bodies are doing with it shifts quietly from decade to decade.

1. In your 20s, your body is still building. Most people reach their peak bone mass somewhere between 25 and 30 [3], which means the habits you have in this decade, including enough protein, calcium, vitamin D and weight-bearing movement, help set the foundations you carry forward.
2. In your 30s, the focus starts to move from building to keeping. After about 30, bone mass begins to decline slowly [3], and muscle mass tends to follow a similar gentle downward path over the following decades if we don't do anything to hold on to it. This is often the decade where life gets busiest, with work, family and everything in between, and meals can become rushed or skipped, which is exactly when protein tends to slip.
3. In your 40s, perimenopause starts for many women, and the fall in oestrogen affects both muscle and bone. The British Dietetic Association suggests eating protein at every meal and doing strength exercise two to three times a week during this stage [4], and the NHS also recommends regular exercise and a healthy diet to help look after your bones [5]. I wrote more about this in my post on protein in perimenopause and menopause.

What genuinely helps across every decade is the combination of enough protein and some form of resistance exercise. A large meta-analysis of 49 trials found that adding protein to resistance training increased gains in lean mass and strength in healthy adults [6], which tells me that protein works best as a partner to movement, rather than as something that does the job on its own. The official way of saying it, and the only way I'll say it, is that protein contributes to a growth in muscle mass, protein contributes to the maintenance of muscle mass, and protein contributes to the maintenance of normal bones, as part of a varied, balanced diet and a healthy lifestyle.

Why the timing across your day matters too

This was the part that surprised me most. Most of us eat a light breakfast, a modest lunch and then most of our protein at dinner, which means our total for the day might look perfectly fine, but it all arrives at once.

In a small but often cited study, researchers gave healthy adults the same total amount of protein in two different patterns for a week each: one spread evenly across breakfast, lunch and dinner, and one skewed towards the evening meal. Muscle protein synthesis over 24 hours was about 25% higher when protein was spread evenly [7]. It was only eight people, so I wouldn't treat it as the final word, however it fits with the wider research suggesting that a moderate amount of protein at each meal is a sensible approach.

Same protein, two shapes of day

24-hour muscle protein synthesis rate (% per hour)

Skewed towards dinner0.056

Spread evenly across three meals0.075

In practice, that might look like eggs or Greek yoghurt at breakfast, lentils, fish or chicken at lunch, and a balanced dinner, rather than a slice of toast in the morning followed by a large steak at night. A serving of protein powder stirred into porridge or blended into a smoothie is simply one easy way of lifting the meal that tends to be lowest, which for most of us is breakfast.

So, how much do you need?

I'd love to give you one neat number, but the honest answer is that it depends on your weight, your age, how active you are and your health, and anyone who promises one figure for every woman isn't telling you the whole story. What I can say is that the UK reference intake is a sensible floor rather than a ceiling, that the research on ageing points towards a little more as the years go on, and that spreading what you eat across your meals seems to matter as much as the total.

If you'd like to read more around this, I've written about whether it's safe to take protein powder every day and whether goat whey is good for building muscle.

Where Kultra fits

I always say that food comes first, and I mean it. Kultra is there for the days when a proper protein breakfast just isn't going to happen, or when you're trying to bring your total up without eating three chicken breasts. A serving is two level scoops, 33g, with 26g of protein, and there are only three ingredients: goat whey protein concentrate, natural vanilla bean and stevia leaf. It isn't lactose free, though, as there's about 1.5g of naturally occurring lactose per serving and it contains milk, so if you've been diagnosed with lactose intolerance, speak to your GP first, and it isn't suitable for anyone with a milk allergy.

If any of this has made you look at your own plate a little differently, I'm really glad. You don't need to be perfect with it, and you certainly don't need to count every gram, but a little more thought about protein, spread across your day, is one of the kindest things you can do for the woman you'll be in twenty years. You can find Kultra here if you'd like to try it, starting with our £10 sample.

-N 🤍

FAQ

How much protein does a woman need a day in the UK?

The UK reference nutrient intake is 0.75g per kilogram of body weight a day, which is about 53g for a 70kg woman. Needs can be higher with age and activity, so check with your GP or a dietitian.

Do women need more protein as they get older?

Research on healthy ageing suggests older adults may benefit from more. The PROT-AGE group recommended 1.0 to 1.2g per kilo for people over 65.

Is it better to spread protein across the day?

A small study found 24-hour muscle protein synthesis was about 25% higher when the same protein was spread evenly across meals rather than loaded into dinner.

How much protein is in a serving of Kultra?

26g in a 33g serving, which is two level scoops.

References

1. Department of Health (1991). Dietary Reference Values for Food Energy and Nutrients for the United Kingdom. Report on Health and Social Subjects 41. HMSO.
2. Bauer J et al. (2013). Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. J Am Med Dir Assoc 14(8):542 to 559. https://pubmed.ncbi.nlm.nih.gov/23867520/
3. American Academy of Orthopaedic Surgeons, OrthoInfo. Healthy Bones at Every Age. https://www.orthoinfo.org/staying-healthy/healthy-bones-at-every-age/
4. British Dietetic Association. Menopause and diet: Food Fact Sheet. https://www.bda.uk.com/resource/menopause-diet.html
5. NHS. Menopause and perimenopause: things you can do. https://www.nhs.uk/conditions/menopause-and-perimenopause/things-you-can-do/
6. Morton RW et al. (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med 52(6):376 to 384. https://pmc.ncbi.nlm.nih.gov/articles/PMC5867436/
7. Mamerow MM et al. (2014). Dietary protein distribution positively influences 24-h muscle protein synthesis in healthy adults. J Nutr 144(6):876 to 880. https://pmc.ncbi.nlm.nih.gov/articles/PMC4018950/