Protein After 40: Why It Matters More Than Ever
The Midlife Metabolism Plot Twist
You used to skip lunch and still fit your jeans.
Now you so much as look at sourdough and your waistband stages a protest.
What changed?
Hormones, responsibilities — and the fact your body’s quietly losing the very thing that keeps your metabolism humming: muscle.
No, this isn’t a call to live on egg whites and protein powder.
It’s a call to understand why protein suddenly matters a whole lot more once you blow out the 40 candles.
The Sciencey Bit
We hit peak muscle mass around age 30-35. After that, things start to decline — slowly at first, then noticeably through our 40s.
From 40 onwards, muscle mass drops by about 3–8% per decade thanks to a sneaky little process called sarcopenia. The decline in oestrogen during perimenopause also accelerates sarcopenia.
By your 50s, the shift is obvious — strength and tone fade faster and by 60, muscle loss can accelerate to more than 10% per decade.
Unless we stay active and include resistance exercise, sarcopenia isn’t just likely — it’s inevitable.
Less muscle = slower metabolism = easier fat gain = harder to bounce back after holidays.
Maintaining muscle through midlife is one of the strongest predictors of healthy ageing
Why Muscle Matters More Than You Think
Muscle isn’t just about looking toned — it’s about staying functional, strong and metabolically healthy as we age.
Beyond helping to prevent frailty, muscle tissue supports your immune system, boosts metabolism and plays a starring role in blood-sugar control.
Every time your muscles flex, stretch or carry you up the stairs, they’re soaking up glucose from your bloodstream to fuel the effort — which helps keep blood sugar steady after eating. In fact, roughly 80% of the glucose floating around after a meal is used or stored in your muscles.
Strong, active muscles also make your body more responsive to insulin, the hormone that moves glucose out of the blood and into your cells. That’s a good thing — because when your cells stop listening to insulin (a condition called insulin resistance), your pancreas has to pump out more and more to get the same effect. Eventually, that system wears thin and blood sugars start to rise, paving the way for type 2 diabetes.
So, strong muscles don’t just move you — they metabolically protect you.
Eating enough protein provides your body with the amino acids it needs to build and maintain muscle, helping to slow the natural muscle loss that comes with age.
But muscle isn’t the only thing that relies on protein. It’s also essential for healthy skin, hair, nails, bones, hormones, enzymes and immune cells — in fact, for almost every structure and function in the body.
Think of protein as your daily maintenance material — the nutrient that keeps you strong, energised and functioning at your best. It’s quite literally the material your body is built from.
Protein helps you:
Keep your metabolism ticking over
Stay fuller for longer
Maintain muscle and bone strength
Recover from exercise and stress
Age well — less frailty, more vitality
Basically, it’s the scaffolding of your midlife health.
How Much Protein Do You Actually Need?
The RDA for protein is a very conservative 0.8g per kg of body weight per day. However, this is what you need to eat to avoid protein deficiency. Studies have shown that even sedentary people would benefit from eating more protein daily.
For women over 40, most research suggests around 1-1.2 g per kg of ideal body weight daily — and ideally spread across meals, not dumped in one go at dinner.
For women engaging in regular physical activity, 1.4–1.6 g/kg/day is suggested.
So that’s 20–30 g per meal for most women
Example day:
Breakfast — Greek yoghurt + berries + handful of nuts
Lunch — Lentil & veggie soup or a chicken salad
Snack — Cottage cheese or edamame
Dinner — Salmon, tofu or lean beef with veggies & whole grains
(See also: [The Complete Guide to Stopping the Diet Cycle for Women Over 40].)
Best High-Protein Foods for Women Over 40
You don’t need to worship whey powder or choke down dry chicken. You need variety.
Animal sources
Cottage cheese, ½ cup = 13 grams of protein
Greek yogurt, ½ cup = 12 grams
1 cup of milk = 8-13 grams depending on the brand
Chicken breast, 100 grams cooked = 31 grams
One egg = 6-7 grams
Salmon, 120 grams cooked = 23 grams
Tuna, 95gram tin = ~13-17 grams
Turkey lunch meat, 100 grams = 13 grams
80% lean Ground Beef, 120 grams cooked = 31 grams of protein
Plant sources of protein
150 grams tofu = 19 grams
½ cup chickpeas = 8 grams
1 cup cooked lentils = 19 grams
1 cup soy milk = 8 grams
½ cup edamame = 9 grams
2 tablespoons of peanut butter = 8 grams
2 tablespoons almond butter = 8 grams
30 grams of pumpkin seeds = 5 grams
1 cup wild rice = 6.5 grams
1 cup of quinoa = 8 grams
Mix them up — your gut microbes love diversity and so does your palate.
Vegetarian women may struggle to achieve protein targets, that’s when protein powders can help. Protein powder, depending on the brand can provide 20-25 grams per serving. Look for those with minimal additives and verified quality, like whey isolate or pea protein.
Common Midlife Protein Myths (Busted)
Myth 1: “Plant protein isn’t as good.”
It’s different, not inferior. Mix your sources and you’ll get all the amino acids you need.
Myth 2: “I’ll bulk up if I eat more.”
Please. You lose muscle easier than you gain it. Protein helps you stay lean, not turn into a bikini competitor. It’s really hard to get too much in when eating real food. Supplement use is usually the cause for excess intake.
Timing Is Everything
Your body can only use so much protein at once. So skipping breakfast then having a protein mountain at dinner is a waste.
Aim for roughly 20–30 g per meal to keep muscle synthesis switched on throughout the day. Research shows muscle protein synthesis peaks with moderate doses and flattens after ~40 g in one sitting.
What Happens When You Don’t Get Enough
You lose muscle and strength.
Your energy crashes mid-afternoon.
You recover slower from exercise (or life).
You get hangry and snacky.
And because muscle is a metabolic organ, the less you have, the slower everything runs — from calorie burn to hormone balance.
Protein isn’t just a nutrient. It’s an anti-meh strategy.
Quick Recap (for the protein-deficient scrollers)
After 40, you lose muscle faster — protein slows that decline.
Aim for 1–1.6 g per kg body weight daily, depending on activity levels.
Spread protein throughout the day.
Combine animal and plant sources.
Protein won’t bulk you up — it’ll keep you vibrant.
Satisfied women make better decisions than hungry ones.
Want to Go Deeper?
[Menopause, Metabolism & Mindset: Why Traditional Diets Fail in Midlife]
[The Complete Guide to Stopping the Diet Cycle for Women Over 40]
[Why Willpower Is Overrated and What Works Instead]
Or grab my free guide “7 Days to Quiet Food Noise” and start re-learning how to fuel your body without the drama of diets. It’s your no-BS midlife plan to calm hormones, quiet cravings and find food peace again.
Final Word
Protein isn’t just about muscle. It’s about maintenance, mood and metabolism.
Eat enough of it, consistently, and you’ll notice you’re not just leaner — you’re clearer, calmer and less bloody hungry.
So give your body what it needs.
References:
Monash University. (2023). A Practitioner’s Toolkit for Managing Menopause.
Queensland Health. (2020). High Protein Food List for Oncology Patients. https://www.health.qld.gov.au/__data/assets/pdf_file/0029/932096/oncol-protein.pdf
Scott, D., Blizzard, L., Fell, J., Giles, G., & Jones, G. (2010). Associations between dietary nutrient intake and muscle mass and strength in community-dwelling older adults: The Tasmanian Older Adult Cohort Study. Journal of the American Geriatrics Society, 58(11), 2129–2134.
Schoenfeld, B. J., & Aragon, A. A. (2018). How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution. Journal of the International Society of Sports Nutrition, 15(10). https://doi.org/10.1186/s12970-018-0215-1
Sims, S. (2020). Roar: How to match your food and fitness to your female physiology for optimum performance, great health, and a strong, lean body for life. Rodale Books.
University of Sydney. (2022). Prioritising protein during perimenopause may ward off weight gain. https://www.sydney.edu.au/news-opinion/news/2022/10/13/prioritising-protein-during-perimenopause-may-ward-off-weight-gain.html