Protein Timing for Longevity: When and How Much Should You Eat?

Photo by Mikhail Nilov

Many researchers now consider muscle mass a predictor of longevity in older adults. That’s because muscle does much more than keep you strong. It's metabolically active tissue that helps your body use glucose and regulate metabolism, while supporting mobility, balance, and independence as you age.

In fact, a recent meta-analysis of more than 76,000 older adults found that sarcopenia, the age-related loss of muscle mass and function, was associated with a 79% higher risk of all-cause mortality and a 90% higher risk of functional decline.

Protein is one of the tools your body uses to maintain that muscle. It provides the amino acids needed for muscle protein synthesis, helping your body continually repair and rebuild muscle tissue. But getting enough protein may only be part of the healthy aging equation. When you eat it could matter, too.

What Is Protein Timing?

Protein timing refers to when you eat protein throughout the day. While researchers once focused on a specific post-workout window for maximizing muscle protein synthesis (MPS), newer research suggests that getting enough total protein each day matters more than following a precise schedule.

Two recent systematic reviews and meta-analyses support this shift. One, published in 2025, compared protein intake before and after exercise and found that timing did not meaningfully affect changes in lean body mass. Another, published in 2024, looked more broadly at protein supplementation in older adults regardless of exercise and found that differences in timing didn't significantly change the results either.

The takeaway? Getting enough total protein each day should be your top priority for maintaining muscle.

How Much Protein Should You Eat Per Day?

The current Recommended Dietary Allowance (RDA) is 0.8 grams of protein per kilogram of body weight per day. But this reflects the basic needs of healthy, sedentary adults. For someone who weighs 150 pounds, that's roughly 55 grams of protein per day.

Your Protein Needs Change As You Get Older

As you age, your muscles become less responsive to the protein you eat, a phenomenon known as anabolic resistance. Research suggests older adults may need about 70% more protein per meal to stimulate the same MPS response as younger adults.

This reduced response is one reason experts recommend 1.0–1.2 g/kg of protein per day for healthy adults over 65, with higher intakes for those who exercise regularly or have certain health conditions. 

Leucine, an essential amino acid that helps activate MPS, may be especially important here. One study found that healthy adults over 60 needed more than twice the amount of leucine recommended by current guidelines, suggesting that meeting those needs may become more challenging with age.

Dileucine combines two leucine molecules and may offer another way to support anabolic signaling. Unlike free leucine, it can be absorbed through the peptide transporter PEPT1, helping it enter circulation quickly. In a small human study, both leucine and dileucine activated anabolic signaling pathways involved in MPS, while dileucine produced a greater MPS response.

How To Make Protein Timing Work for You

Find your daily target. Your needs depend on factors like age, activity level, and health, so consider working with a healthcare provider or registered dietitian to determine the right target for you.

Spread protein across your meals. Research suggests aiming for around 25–30 grams of high-quality protein per meal, particularly for older adults. This balanced approach may stimulate MPS more effectively than concentrating most of your protein in one meal.

Pair protein with resistance training. Along with adequate protein, resistance exercise supports muscle growth and physical function, helping you build and maintain muscle for the years ahead.

Building muscle takes time, but the strength you preserve can pay off for decades.

Devan Ciccarelli is a NASM-Certified Personal Trainer, Nutrition Coach, and Women's Fitness Specialist who writes on health and lives in Florida with her two kids.