The Journal

Precision on Protein

How much protein do women actually need in midlife?

Dr Amy Shacaluga·29 September 202617 min read

If you've been told that women "need less protein", or that plant protein "doesn't count", you were given a slogan, not a plan. As a consultant obstetrician and gynaecologist, I hear both of these in clinic almost every week. Usually they come from women doing their best on advice that was never built for them.

Protein is what your body uses to repair muscle, support the framework of your bones, make enzymes and hormones, and keep you full between meals. How much you eat matters. So does the quality, and so does what you ask your muscles to do. The right answer for you depends on your body, your kidney function, your medications and how you train. That's the heart of Precision Health: assess first, then personalise.

First, whose bodies were studied?

Much of the early research on protein and muscle was done in men (no surprises). That includes the most quoted studies on how much protein a meal needs, how that changes with age, and how plant and animal proteins compare [9,10,11,14]. Even in research on ageing muscle, most studies have enrolled men. What happens in a man's body doesn't automatically tell us what happens in a woman's in midlife [15].

So in this article I've put the women-specific evidence first: consensus guidance for postmenopausal women, trials that recruited only women, and newer studies of muscle in postmenopausal women [4,6,7,15,16,20,21]. Where the evidence for women is still thin, I'll say so.

Why your protein needs change

The UK reference intake for healthy adults is about 0.75 g of protein per kg of body weight per day [1]. That figure comes from the Scientific Advisory Committee on Nutrition (SACN). It's a population minimum to keep you in balance, not a target for protecting muscle as you age.

Expert groups on ageing suggest that many people over about 65 need more than that: roughly 1.0 to 1.2 g/kg/day, and at least 1.2 g/kg/day if you're active or doing strength work. They recommend more again during illness, unless you have advanced chronic kidney disease (CKD) [2,3]. That's expert consensus. The official UK figure hasn't changed. I've worked these figures through for different body weights in the table further down.

This matters in midlife because perimenopause and menopause aren't only about hot flushes. Falling oestrogen is linked to faster loss of lean muscle. It's also linked to a weaker response from muscle to the same protein meal, which is called anabolic resistance. In practice, each meal needs a clearer protein signal, and grazing on "quick fix" toast all day won't give you that.

Protein also keeps you full. Spreading a decent amount across the day tends to steady appetite better than a small breakfast followed by a huge dinner. For bones, protein works alongside calcium, vitamin D and weight-bearing exercise, not instead of them. When calcium intake is adequate, higher protein is linked to better bone health in older adults. It doesn't "leach" calcium from bone [4,5]. A very low-protein diet isn't bone-friendly in later life, and neither is protein powder without any strength work.

Perimenopause and postmenopause aren't the same

Perimenopause is the years of cycle change before your final period. Postmenopause or menopause starts once you've gone twelve months without a period. The research on the two is not equally strong.

Menopause has the clearer evidence. The European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) consensus on bone and muscle health after menopause recommends:

• about 1.0 to 1.2 g/kg/day of protein
• at least 20 to 25 g of high-quality protein at each main meal, whatever your weight
• calcium of around 1,000 mg a day
• vitamin D of around 800 IU a day
• regular physical activity [4]

One detail I find reassuring is about women who already lift. In a randomised trial of postmenopausal women on a strength programme, raising protein from about 0.8 to 1.2 g/kg/day did not add extra lean mass over ten weeks [6]. Lifting drives the change. Protein supplies the building material. A 2022 meta-analysis of whey protein in postmenopausal women found the same thing. Gains in arm strength and lower-limb lean mass showed up only when whey was combined with resistance training, not when it was taken on its own [7].

Postmenopausal women's muscle does respond to protein, and it responds to strength exercise too. A 2024 study measured this directly in women after menopause, rather than borrowing results from men [15]. Reviews of muscle and bone after menopause reach the same practical conclusion: protein and vitamin D work best alongside a proper exercise plan [16].

Perimenopause has less evidence. One observational study found differences in strength, leg muscle and lifestyle between women before and during perimenopause [17], but it didn't test protein doses. A trial in untrained midlife women (peri- and postmenopausal ages) found that strength training improved strength; adding leucine tablets did not add further benefit for muscle or strength [18]. So far, though, there isn't a large set of protein trials in perimenopausal women. My approach is to use the postmenopausal guidance as a baseline for midlife, then personalise from there.

Around the final period, many women notice they feel less strong, recover more slowly, and change shape even when the scales barely move. None of that is a character flaw. Muscle is metabolically active tissue. If you lose it quietly, energy, insulin sensitivity and balance can all drift the wrong way.

Strength training and protein work as a pair

Resistance training tells your muscles to grow or remodel. Protein supplies the amino acids they need to do it. A large meta-analysis of adults found that adding protein to a training programme gave small but real extra gains in strength and muscle. Around 1.6 g/kg/day, further gains were limited in that analysis [8]. For postmenopausal women specifically, the trials above tell the same story: training comes first, and protein supports it [6,7].

Timing matters less than fitness marketing suggests. Getting enough protein across the whole day, with a good serving in the hours around training when that fits your life, matters far more than a stopwatch. You don't need to worry about an "anabolic window". You do need the squat, the hinge, the push and the pull.

Amino acids in plain language

Proteins are chains of amino acids. Nine of them are essential amino acids, which means your body can't make them, so they have to come from food.

Complete proteins contain all nine in useful amounts. Most animal foods are complete, and so are soy, quinoa and many modern blends. Incomplete means one food is a bit low in one or more of them. It doesn't mean the food is useless. Eating a variety of plants over the day covers the full set.

Leucine: the signal that tells muscle to build

Leucine is one of the nine essential amino acids, and it does more than act as a building block. Muscle cells sense it directly. Leucine switches on a signalling pathway called mechanistic target of rapamycin complex 1 (mTORC1), which starts muscle protein synthesis [29]. I think of total protein as the bricks and leucine as the site manager who tells the builders to start work.

This matters more in midlife. With anabolic resistance, ageing muscle needs a louder signal before it responds [29]. A meal can look like it has plenty of protein and still not send that signal clearly if its leucine content is low.

The ESCEO guidance for postmenopausal women suggests that about 2 to 2.5 g of leucine per meal may be beneficial, alongside 20 to 25 g of protein [4]. In practice, I aim for about 2 to 3 g of leucine at each main meal. The per-meal protein amounts in the body-weight table below usually get you there. For a 55 kg woman who is strength training, that's about 22 to 29 g of protein per meal. For a 75 kg woman, it's about 30 to 40 g.

Dairy, meat, fish, eggs and soy are the richest sources of leucine. Most pulses and grains contain less per portion, so plant-based meals often need a larger serving or a combination (tofu with lentils, for example). The food table below shows how that works in real portions.

Plant or animal? It isn't either/or

What's true: gram for gram, some plant proteins are less potent for muscle building than dairy protein. That's partly because of digestibility, amino acid mix and lower leucine [12]. Protein quality scores such as the Protein Digestibility-Corrected Amino Acid Score (PDCAAS) and the newer Digestible Indispensable Amino Acid Score (DIAAS) try to capture this. Animal proteins and soy usually score well, while many cereals score lower unless they're combined or eaten in larger amounts [13]. Blends that combine several plant sources can close much of that gap [12,14].

In practice, if you eat mostly plants, you may need a little more protein in total. It helps to vary your sources across the day (beans with grains, soy, nuts and seeds), or to use a fortified blend if you train hard. We don't yet have long-term trials comparing plant and animal protein in midlife women, so the safest message is: enough protein, plenty of variety, and training.

If you eat meat, you can still have plants at every meal. If you eat mostly plants, build your meals around tofu, tempeh, edamame, lentils or soy yoghurt. A leucine-rich powder can help if eating enough food is a struggle.

Protein in real portions

Values are from USDA FoodData Central and have been rounded [28]. UK products vary, especially tofu and cottage cheese, so check the label.

How to use this: a salmon fillet or a portion of chicken reaches a meal's protein and leucine target on its own. A bowl of lentils doesn't. Add tofu, a scoop of Greek or soy yoghurt, or a second pulse, and it does. Two eggs on toast is a good start to a breakfast, but not a full protein meal. Add cottage cheese or smoked salmon to get there.

Where does creatine fit?

Creatine is one of the few supplements with a solid evidence base, and it's getting a lot of attention in women's health [27]. Your body makes some creatine, and you get more from meat and fish. It's stored in muscle, where it helps supply energy for short, hard efforts such as lifting. The theory is that you can train a little harder, and your muscles adapt a little more.

What the evidence shows

• Muscle and strength in older adults: a meta-analysis of 22 trials (average age 57 to 70) found that creatine added to strength training gave about 1.4 kg more lean mass than training alone, with small extra gains in strength [22].
• Older women specifically: the picture is more modest. A meta-analysis limited to older women found a small improvement in upper-body strength. Lower-body strength improved only in studies lasting six months or more, and there was no clear change in muscle mass. The authors noted that the evidence is limited and that higher-quality trials are still needed [23].
• Bone: a one-year trial in postmenopausal women who lifted weights found less bone loss at the hip with creatine [24]. However, a larger two-year trial of 237 postmenopausal women found no benefit for bone density. There were small benefits for hip bone shape, lean mass and walking speed [25]. Creatine isn't a bone treatment.

My take: creatine is a reasonable, optional add-on for a woman who is already strength training and eating enough protein. It isn't a substitute for either. It's more likely to help if you eat little or no meat and fish.

If you're considering it

• The usual dose is 3 to 5 g of creatine monohydrate a day. You don't need a "loading" phase [26].
• Taking it can cause some early water weight gain on the scales. That's water held in muscle, not fat [26].
• In healthy people, studies lasting months to years haven't shown kidney harm [22,26].
• Creatine is broken down into creatinine [26], so it can raise the creatinine level on a blood test. Tell your GP or clinician you're taking it, so your kidney results are read correctly.
• Don't start creatine without advice if you have kidney disease, are pregnant or breastfeeding, or take medications that affect your kidneys.

What actually helps: starting points

These are starting points, not prescriptions. Here's what the daily and per-meal targets look like at different body weights:

Whatever your weight, aim for at least 20 to 25 g of protein at each main meal after menopause [4]. If you're living with a higher body weight, I usually work out your target from an adjusted weight rather than your scale weight, so the number isn't inflated. That's a calculation to do with your clinician.

• On the plate: fill a quarter to a third of your plate at lunch and dinner with a clear protein source. Don't let breakfast be toast alone.
• For your bones: combine protein with enough calcium, adequate vitamin D and weight-bearing exercise [4,5].
• Creatine (optional): 3 to 5 g a day may add a little to your strength training. It doesn't replace training or protein [22,23,26].
• Get assessed first if you have kidney disease, are pregnant, have or have had an eating disorder, or are losing weight without explanation. Please don't start a high-protein plan or supplements on your own.

A Precision Health pearl

Measure before you treat. A "high-protein" plan from social media can still be low in leucine, lack a real training stimulus, or be unsafe if you have CKD.

My lifestyle takeaway

Lift something that feels heavy for you, two or three times a week. Put a proper serving of protein on your plate at every main meal, with enough leucine to send the signal. Choose animal, plant or both, whichever suits you. Adjust for your season of life. And remember that the famous gram rules mostly came from men's bodies, while your plan should start with yours.

From my clinic

In clinic, I rarely start with a number. I start with what you ate yesterday, what your week of movement looks like, and your bloods and history. Only then do we set a target that fits your life. For some women in early postmenopause who are already lifting, hormone replacement therapy (HRT) is part of the same conversation. There's early trial evidence that oestrogen therapy may increase muscle gains from strength training [19], and I discuss that case by case.

If you'd like help working out what this means for your body, you can book a consultation through the booking link at www.dramyshacaluga.co.uk.

This article is general education, not personal medical advice. It is not for emergencies. For urgent care, call 999 or NHS 111.

References

1. SACN. Statement on nutrition and older adults living in the community. 2021. (Overview: van Dijk et al. Br J Nutr 2021; PMID 33334383.)
2. Bauer J et al. Evidence-based recommendations for optimal dietary protein intake in older people: PROT-AGE Study Group. J Am Med Dir Assoc 2013;14:542-59. PMID 23867520.
3. Deutz NEP et al. Protein intake and exercise for optimal muscle function with aging: ESPEN Expert Group. Clin Nutr 2014;33:929-36. PMID 24814383.
4. Rizzoli R et al. The role of dietary protein and vitamin D in maintaining musculoskeletal health in postmenopausal women: ESCEO consensus. Maturitas 2014;79:122-32. PMID 25082206.
5. Rizzoli R et al. Benefits and safety of dietary protein for bone health. Osteoporos Int 2018;29:1933-48. PMID 29740667.
6. Rossato LT et al. Higher protein intake does not improve lean mass gain when compared with RDA recommendation in postmenopausal women following resistance exercise protocol: an RCT. Nutrients 2017;9(9):1007. PMID 28895933.
7. Kuo YY et al. Effect of whey protein supplementation in postmenopausal women: a systematic review and meta-analysis. Nutrients 2022;14(19):4210. PMID 36235862.
8. Morton RW et al. Protein supplementation and resistance training-induced gains in muscle mass and strength in healthy adults: SR, MA and meta-regression. Br J Sports Med 2018;52:376-84. PMID 28698222.
9. Moore DR et al. Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. Am J Clin Nutr 2009;89:161-8. PMID 19056590.
10. Moore DR et al. Protein ingestion to stimulate myofibrillar protein synthesis requires greater relative protein intakes in healthy older versus younger men. J Gerontol A Biol Sci Med Sci 2015;70:57-62. PMID 25056502.
11. Tang JE et al. Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis in young men. J Appl Physiol 2009;107:987-92. PMID 19589961.
12. van Vliet S, Burd NA, van Loon LJC. The skeletal muscle anabolic response to plant- versus animal-based protein consumption. J Nutr 2015;145:1981-91. PMID 26224750.
13. FAO. Dietary protein quality evaluation in human nutrition. Food and Nutrition Paper 92. Rome: FAO; 2013. See also Moughan PJ, Lim WXJ. Front Nutr 2024; PMID 39021594.
14. Pinckaers PJM et al. The muscle protein synthetic response to the ingestion of a plant-derived protein blend does not differ from an equivalent amount of milk protein in healthy young males. J Nutr 2023;152:2734-43. PMID 36170964.
15. McKenna CF et al. Postabsorptive and postprandial myofibrillar protein synthesis rates at rest and after resistance exercise in women with postmenopause. J Appl Physiol 2024;136:1388-99. PMID 38385186.
16. Agostini D et al. Muscle and bone health in postmenopausal women: role of protein and vitamin D supplementation combined with exercise training. Nutrients 2018;10(8):1103. PMID 30115856.
17. Cabre HE et al. Differences in strength, leg lean mass, and lifestyle factors between premenopausal and perimenopausal women. Clin Physiol Funct Imaging 2022;42:460-4. PMID 35762156.
18. Funderburk LK et al. Efficacy of L-leucine supplementation coupled with resistance training in untrained midlife women. J Am Coll Nutr 2020;39:316-24. PMID 31577520.
19. Dam TV et al. Transdermal estrogen therapy improves gains in skeletal muscle mass after 12 weeks of resistance training in early postmenopausal women. Front Physiol 2021;11:596130. PMID 33542694.
20. Devries MC et al. Protein leucine content is a determinant of shorter- and longer-term muscle protein synthetic responses at rest and following resistance exercise in healthy older women: a randomized, controlled trial. Am J Clin Nutr 2018;107(2):217-26. PMID 29529146.
21. Devries MC et al. Leucine, not total protein, content of a supplement is the primary determinant of muscle protein anabolic responses in healthy older women. J Nutr 2018;148(7):1088-95. PMID 29901760. (Erratum: PMID 30830198.)
22. Chilibeck PD et al. Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis. Open Access J Sports Med 2017;8:213-26. PMID 29138605.
23. dos Santos EEP et al. Efficacy of creatine supplementation combined with resistance training on muscle strength and muscle mass in older females: a systematic review and meta-analysis. Nutrients 2021;13(11):3757. PMID 34836013.
24. Chilibeck PD et al. Effects of creatine and resistance training on bone health in postmenopausal women. Med Sci Sports Exerc 2015;47(8):1587-95. PMID 25386713.
25. Chilibeck PD et al. A 2-yr randomized controlled trial on creatine supplementation during exercise for postmenopausal bone health. Med Sci Sports Exerc 2023;55(10):1750-60. PMID 37144634.
26. Kreider RB et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr 2017;14:18. PMID 28615996.
27. Smith-Ryan AE et al. Creatine supplementation in women's health: a lifespan perspective. Nutrients 2021;13(3):877. PMID 33800439. PMC7998865.
28. US Department of Agriculture. FoodData Central, SR Legacy (FDC IDs 171477, 175168, 173417, 171287, 172475, 174272, 172421, 173757, 168411). fdc.nal.usda.gov.
29. Zhao Y et al. Advances in the role of leucine-sensing in the regulation of protein synthesis in aging skeletal muscle. Front Cell Dev Biol 2021;9:646482. PMID 33869199. (Xia Z corresponding.)