By Rachael Schultz
The science of building strength and muscle feels challenging enough when you’re in your peak athletic years — let alone when time starts working against you as you age. It’s a hard truth that our bodies naturally lose muscle mass starting in our 30s or 40s, with the process picking up speed once we hit 65. It’s called sarcopenia, and some studies report we lose an average of a whopping 30 to 50 percent of our muscle mass between 40 and 80 years old.
That doesn’t mean you should give up on the gym now. Your best weapon — and a highly effective one, at that — to build and maintain muscle as you age: Strength train and eat more protein.
Now, you’ve probably been hearing the advice to eat more protein since, well, you first picked up a dumbbell. It’s true: Protein can help you build muscle, stay full longer, and give you more energy.
But as your body changes in middle age and beyond, so too does your protein needs. What’s more, what you eat now has a massive impact on how healthy you’ll stay for the decades to come.
Here are the most important facts you need to understand about protein in your 40s, 50s, and beyond.
1. Eating more protein can help you stay mobile and independent as you age.
We often associate protein with more energy and muscle, and while it will certainly help with both, eating more of the macronutrient now can keep you spry in the long run.
A 2018 study in the American Journal of Epidemiology analyzed the amount of protein men and women ate at 50+ years old and then how they fared 12 years later at doing physical tasks without help. Those who ate a high-protein diet in middle age (at least 1.2 grams per kilogram of body weight per day) were 41% less likely to need assistance 12 years later on things like going up and down stairs, kneeling and crouching, walking 0.5 miles, and lifting heavy items at home.
Even better news: The most able-bodied in the study were people who not only ate at least 1.2 grams of protein per kilogram of body weight per day but who also were very physically active, had good muscle mass, or had low body mass — all of which you’re aiming to achieve with MPC.
2. Eating more protein now can stave off disease.
We all know the secret to minimizing your future disease risk is eating a wide range of micronutrients and a minimal amount of processed, carcinogenic foods. But protein holds serious power, too.
Women who ate sufficient protein in mid-life were significantly less likely to develop chronic diseases or impairments and had better mental health 30 years later, reports a 2024 study in The American Journal of Clinical Nutrition. In particular, women who ate sufficient protein mostly from plant sources were 46% more likely to age healthily compared with those who ate low amounts of protein (more on plant protein in a minute).
Other research shows both men and women who ate sufficient dietary protein during middle age were significantly less likely to develop osteoporosis later in life, as well as sarcopenia (particularly among women).
We lose an average of 30 to 50 percent of our muscle mass between 40 and 80 years old.
3. The older you get, the more protein you have to eat for the same effect.
As we age, our muscles become less responsive to protein intake and exercise, making it harder to build and maintain muscle — something known as “anabolic resistance.”
You’ve no doubt noticed working out a few times a week doesn’t have the same effect now as it did when you were 20. The same concept applies to how your muscles can synthesize protein — you have to put in more to gain the same effect.
Anabolic resistance typically starts around 40 years old, but the effects become noticeable around 50.
The standard recommendation for daily protein intake across your lifespan is around 0.8 grams of protein per kilogram of bodyweight per day. But more and more research is coming out to say that once you hit midlife — certainly after 65 — you should aim for closer to 1.2 grams of protein per kilogram of bodyweight per day (g/kg/d). (That’s 84 grams of protein for a 155-pound person.) You can go up to 2.5 grams/kilograms per day without negative effects, research shows.
In one study, older, post-menopausal women who were otherwise healthy but ate less than 1.1 grams/kilograms per day of protein not only had higher body fat than those who ate higher amounts of the macro but also their upper and lower mobility was impaired. So, you need more protein than you think to stay healthy.
4. Post-workout protein matters less than daily protein.
For a long time, we’ve been taught it’s crucial to consume protein not only every couple of hours but, more specifically, within the first 30 to 60 minutes post-workout. This adds protein during your anabolic window, maximizing your muscle growth and recovery.
But more and more research is now saying the timing of your protein matters less than your overall daily intake.
A 2024 study analysis in Ageing Research Reviews found eating more protein does indeed improve the muscle mass of people over 65 years old, but it doesn’t much matter the timing or frequency of eating it. A 2020 meta-analysis in The Journal of Nutrition found similar results across people 18 to well above 55 years old — increasing their overall protein intake helped improve lean body mass but strategic timing didn’t make much of a difference.
That said, there are many ways you can go about increasing your daily intake. Research shows adding more protein to every meal and eating protein-rich meals more often are both super helpful for increasing your total daily protein intake and improving your muscle protein synthesis.
Overall, aim to consume at least 1.2 grams/kilograms per day of protein or 30 grams of protein per meal.
5. Plant protein really is best.
There’s a long-held belief that animal-derived protein — everything from red meat to whey protein powder — is far superior to plant proteins when it comes to having the best amino acid profile to build muscle and get fit.
But the research is clear: Plant protein is just as capable of building muscle — and significantly better for your long-term health.
People who got the majority of their protein from plants had the best health later in life compared to those who ate protein largely from animals or dairy, according to a 2024 study in The American Journal of Clinical Nutrition.
As most of us know, eating animal protein increases your risk for cardiovascular disease, type 2 diabetes, high blood pressure, and body weight. More specifically, you want to stay away from red and processed meats.
Meanwhile, studies show that eating plant protein lowers your risk of many of these health problems.
You should aim to get the majority of your protein from tofu and edamame (which is especially great for bone density in postmenopausal women and does not affect your hormone levels, despite long-shared rumors), as well as navy beans, various seeds (pumpkin, sesame, hemp), peanuts, and lentils. These plant protein sources are all high in the amino acid leucine as well as protein, which research shows helps improve muscle protein synthesis in older women (65 to 75) compared to protein sources without the amino acid. Leucine is especially helpful for anyone with sarcopenia.
Other great sources of plant protein: all forms of beans, chickpeas, quinoa, peas, and spinach.
We also highly recommend incorporating high-protein, omega-3-rich fish (salmon, sardines, cod, and mackerel) in your diet, which are very good for healthy aging.
If you’re looking for a protein powder, look for one made from soy, pea, and/or rice protein with leucine, which studies show are equally effective on body composition compared to whey.
Related: Plant-Based Eating for Muscle Growth
What To Eat
Here are a few hard-and-fast rules about how to approach protein:
- Aim to consume at least 1.2 grams/kilograms per day of protein or 30 grams of protein per meal.
- Focus on eating more protein at every meal and eating protein more often.
- Protein should come from leucine-rich plant sources, including tofu, edamame, navy beans, seeds, peanuts, and lentils.
- Protein can also come from salmon, sardines, cod, mackerel, any beans, chickpeas, quinoa, peas, and spinach.
Related: Manage Your Macros
