The Bottom Line First

This week's research supports a practical pattern for maintaining muscle as we age: include enough protein across the day and pair it with progressive resistance training. The findings also put limits on the headlines. Plant protein can work, but one recent trial did not prove vegetarian and omnivorous diets produced identical muscle gains. And a newly described exercise mechanism has only been tested in animals.

The research mostly involved adults over 60, or adults 55 and older in one trial. It offers useful context for people in their 50s, but it is not a personalized prescription.

Older Muscle Builds Protein More Slowly—Exercise Still Helps

A 2026 systematic review and meta-analysis included 46 studies and 1,280 participants. It found lower muscle protein synthesis in older adults at rest and after eating in many of the studies. The evidence on muscle protein breakdown was mixed; it did not show a consistent pattern of older muscle breaking down protein faster.

The encouraging part: after resistance exercise, most of the studies that compared age groups found no clear difference in muscle protein synthesis. The authors conclude that an adequately challenging resistance-training stimulus, paired with enough protein, can help older muscle respond. This does not mean exercise erases every age-related difference, but it is a strong reason to keep strength work in the plan.

Plant Protein Can Support Muscle, With a Small Caveat

A systematic review of 43 randomized trials found a small overall advantage for animal protein on muscle-mass outcomes. In the older-adult subgroup—nine studies of people 60 and up—the difference was not statistically clear. The review found no significant overall differences in strength or physical performance. A 2026 review in *Frontiers in Nutrition* also reports similar muscle-mass outcomes for soy and milk protein in direct comparisons.

That is reassuring if your meals lean plant-based, while keeping the evidence honest: plant sources differ, and getting enough total protein still matters. Soy, beans, lentils, tofu, tempeh, dairy, eggs, fish, and meat can all fit into a muscle-supportive eating pattern.

What the Vegetarian Resistance-Training Trial Found

In the IMPACT randomized trial, 108 adults aged 55 and older completed 12 weeks of resistance training three times per week. One group followed a lacto-ovo vegetarian diet and the other an omnivorous diet; both received counseling to reach at least 1.2 grams of protein per kilogram of body weight per day.

Both groups gained appendicular muscle mass, and leg-press strength and chair-stand results improved in both groups without a clear between-group difference in those functional measures. However, the study did not establish that the vegetarian diet was noninferior for muscle mass, and average protein intake was lower in that group. The careful takeaway is that people in both groups made progress while training and meeting the protein target—not that the diets were proven identical.

Protein Targets: A Starting Point, Not a Rule

Expert guidance from ESPEN suggests about 1.0–1.2 grams of protein per kilogram of body weight per day for many healthy older adults, with higher needs in some illness or malnutrition situations. A recent review discusses about 0.4 g/kg per meal as one way to distribute protein. These are population-level guideposts, not requirements for every person. Body size, activity, appetite, medical conditions, and clinician-directed diets can change the right approach.

If protein is low at breakfast, consider adding eggs, Greek yogurt, cottage cheese, tofu, milk, or leftovers. For a fuller explanation and food examples, see How Much Protein Do You Need After 50 to Keep Muscle?. If you have kidney disease or another condition affecting your diet, ask your clinician or registered dietitian before increasing protein.

An Interesting Clue From Flies and Mice

Duke-NUS researchers reported that a protein called DEAF1 rises with age and disrupts the balance between muscle growth and cellular cleanup. In experiments with fruit flies and older mice, changing DEAF1 levels affected muscle function, and exercise shifted the system in a favorable direction. This is early animal research, not evidence of a treatment or a specific human training prescription.

What to Do This Week

  • Do two or three resistance sessions at a level that fits your experience and health.
  • Notice whether breakfast and lunch include a useful protein source.
  • Choose plant or animal foods you enjoy, and aim for a balanced pattern across the day.
  • Treat gram targets as discussion points for your clinician or dietitian, especially if you have a medical condition.

The repeatable message is simple: train your muscles, eat well enough to support that work, and avoid expecting one food or supplement to do the job alone. Want help connecting training and nutrition to your goals? Book a free 20-minute strategy session.

This article is for general education and is not medical advice. Protein and exercise plans should be adapted to your health, medications, symptoms, kidney function, and abilities.