By BRENDA DAVIS, R.D.
Protein is having quite a moment. Grocery store shelves are crowded with protein powders, bars, shakes, cereals—even products we never imagined needed a protein boost. At times, our cultural obsession with protein can seem excessive. Yet amid all the hype is an important reality: protein really does become more important as we age.
For adults over 50, however, the goal isn’t to chase protein for its own sake or assume that more is always better. It’s to preserve something extraordinarily precious: muscle. Muscle lets us climb stairs, carry groceries, recover from illness, maintain metabolic health, avoid falls, and keep doing the things we love. In many ways, muscle is a retirement account for physical independence, and as we age, we want to keep making deposits.
Do Older Adults Need More Protein?
The current U.S. and Canadian Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight per day, and it does not increase with age. But the RDA is designed to meet the basic needs of nearly all healthy people; it isn’t necessarily the amount that optimizes muscle preservation and function in later life.
Several expert groups have concluded that older adults benefit from more. The international PROT-AGE Study Group and an expert group convened by the European Society for Clinical Nutrition and Metabolism (ESPEN) recommend approximately 1.0–1.2 g/kg/day for healthy older adults. For people with acute or chronic illness, malnutrition, or conditions that accelerate muscle loss, recommendations generally rise to 1.2–1.5 g/kg/day.
For a healthy 150-pound (68-kg) adult, 1.0–1.2 g/kg translates to roughly 68–82 grams of protein per day.
Why the increase? With age, our muscles become somewhat less responsive to the anabolic signals provided by dietary protein. This phenomenon is called anabolic resistance. Older muscles may require a stronger stimulus to generate the same muscle-protein-building response. Illness, inflammation, inactivity, and periods of bed rest can further increase protein needs.
Another challenge is that calorie requirements generally decline with age, while protein needs do not. We have less room for nutritional passengers—foods that provide calories without bringing much nutrition along for the ride.
But What About the enzyme called mTOR?
Within the plant-based community, some worry that eating more protein, particularly protein rich in leucine, activates mTOR (mechanistic target of rapamycin). mTOR is an enzyme at the center of a cellular signaling system that senses nutrients and energy and, when activated, promotes processes involved in growth, repair, and muscle protein synthesis.
But what is sometimes overlooked is that mTOR activation is not inherently harmful. Protein-rich meals and resistance exercise temporarily increase mTORC1 signaling in muscle, helping stimulate muscle protein synthesis—a normal and desirable response, particularly in older adults.
The longevity concern relates more to chronic or dysregulated mTOR signaling. Persistent energy and nutrient excess, obesity, insulin resistance, and elevated insulin and growth-factor signaling can create a metabolic environment that favors sustained mTORC1 activity. Western dietary patterns rich in excess calories and highly refined, energy-dense foods can contribute to this environment.
By contrast, healthful plant-based diets are generally high in fiber and lower in energy density and are associated with better metabolic health. Eating enough plant protein to preserve muscle is very different from chronic overnutrition.
The goal isn’t to keep mTOR permanently switched off. For older adults, deliberately under-eating protein to suppress mTOR could come at the cost of muscle, strength, resilience, and independence.
Can Plant Protein Do the Job?
Absolutely.
Beans, lentils, peas, tofu, tempeh, edamame, soy milk, nuts, seeds and whole grains can provide all of the essential amino acids required to build and maintain muscle. Some plant proteins may be slightly less digestible or have less leucine per gram than some animal proteins, so including protein-rich foods at meals is especially important.
It is encouraging to note that a recent randomized crossover trial in active older adults found comparable rates of daily muscle protein synthesis whether dietary protein came entirely from plants or predominantly from animal sources, when the diets provided the same amounts of energy and protein.
And the “protein package” matters. Legumes bring protein packaged with fiber, potassium, magnesium, antioxidants and phytochemicals. Nuts and seeds deliver protein along with unsaturated fats and minerals. Soy foods provide high-quality protein plus beneficial phytochemicals. Animal protein foods, by contrast, contain no fiber, and many, particularly red and processed meats and higher-fat dairy products. contribute substantial amounts of saturated fat. Prospective research consistently finds favorable health associations when plant protein foods replace certain animal protein foods, particularly red and processed meats, including lower cardiovascular and all-cause mortality.
Practical Protein Pointers
Rather than obsessing over protein numbers, make protein-rich foods a deliberate part of each meal. Start breakfast with soy milk, tofu, nuts, seeds or a protein-rich whole grain. Build lunch around lentils, beans or chickpeas. Feature tofu, tempeh, edamame, seitan or legumes at dinner. For many older adults, aiming for roughly 20–30 grams at a main meal can be a useful practical strategy, although individual needs vary.
And remember that protein is only half of the muscle equation.
Protein provides the building blocks; resistance exercise provides the signal.
We cannot eat our way to strong muscles. We need to give those muscles a reason to stay.
Getting older doesn’t mean resigning ourselves to becoming weaker. With enough protein, nourishing plant foods, and regular resistance exercise, we can keep investing in strength, resilience, and independence for decades to come.
About Brenda Davis, R.D.
Brenda Davis, RD, is one of the world’s leading plant-based dietitians, an internationally acclaimed speaker, and award-winning author specializing in plant-based nutrition. She has delivered keynote presentations in 28 countries across six continents and has written or co-authored 14 books, with more than one million copies in print.
Brenda has published extensively in peer-reviewed journals and consumer publications and has contributed to groundbreaking research, including serving as the lead dietitian on a randomized controlled trial of type 2 diabetes in the Marshall Islands. A past chair of the Vegetarian Nutrition Dietetic Practice Group of the Academy of Nutrition and Dietetics, she was inducted into the Vegetarian Hall of Fame in 2007 and received the Plantrician Project’s Luminary Award in 2022. She lives in Calgary, Alberta, Canada.
To find out more go to Brenda’s website.