First, the caveats:

As you know, we are not doctors, nor are we nutritionists. The best nutrition protocol for anyone is HIGHLY individual and depends on one’s health status, unique biochemistry, preferences, personal philosophies, resources, etc.

We are not trying to (nor will we ever!) suggest what you should eat. We simply want to share what the research does and does not seem to show regarding dietary protein — bearing in mind that research can show just about anything, depending upon how studies are designed.

So, if what you’re doing is working for you, as in: strong bones, enough muscle for your desired activities, ability to recover from injury & illness, consistent energy and satisfactory satiety, don’t change anything! If you’re fine, you’re fine!

But if you feel that anything is lacking in those foregoing categories, you might try experimenting (in consultation with your healthcare provider, of course), paying close attention to how your body responds. Ultimately, YOU are the expert on you.

One of the key mechanisms by which protein supports muscle health is through myofibrillar (muscle fiber) protein synthesis (MPS), or the process of turning the protein we eat into muscle in our bodies. As we get older, our bodies become less sensitive to the signals that trigger MPS. This means that older adults typically need more protein per meal to initiate the same level of muscle-building response that younger people might achieve with less. Research suggests that at least 30 grams of protein per meal is needed to effectively stimulate MPS in older adults.

Timing also plays a role. Since your body has been fasting overnight, the first meal of the day becomes especially important. Starting your morning with a solid dose of protein helps “wake up” your muscle-building machinery, setting a strong foundation for the rest of the day. Even if you’re not ready to commit to a full gram of protein per pound of ideal body weight per day, making that first meal protein-rich can have a meaningful impact.

Here are summaries of the work of a couple of the most prominent researchers in this area:

Dr. Stuart Phillips

Dr. Stuart Phillips, a leading researcher in muscle physiology at McMaster University, has extensively studied how older adults can maintain and build muscle mass to combat age-related decline, known as sarcopenia. His research highlights several key strategies:

Understanding Anabolic Resistance

As people age, their muscles become less responsive to stimuli that typically promote muscle growth, such as protein intake and resistance exercise. This phenomenon, termed “anabolic resistance,” means that older adults require higher amounts of protein and more targeted exercise to achieve the same muscle-building effects as younger individuals .

Protein Intake Recommendations

Dr. Phillips emphasizes the importance of adequate protein consumption for older adults:

• Increased Protein Needs: Older individuals may need up to 40 grams of high-quality protein per meal to effectively stimulate muscle protein synthesis, compared to about 20 grams for younger adults .
• Leucine-Rich Proteins: Proteins high in the amino acid leucine, such as whey protein, are particularly effective in promoting muscle growth in older adults .
• Even Distribution: Spreading protein intake evenly across meals throughout the day can optimize muscle protein synthesis .

Resistance Training Benefits

Engaging in resistance exercise is crucial for older adults:

• Muscle Protein Synthesis: Resistance training can significantly enhance muscle protein synthesis, even in the presence of anabolic resistance .
• Adaptability: Older muscles retain the ability to adapt to resistance training, leading to improvements in muscle mass and strength .
• Combined Approach: Pairing resistance exercise with adequate protein intake yields the most substantial benefits for muscle health .

Broader Health Implications

Maintaining muscle mass is not only vital for physical strength but also for overall health:

• Longevity: Muscle health is linked to increased longevity and reduced risk of chronic diseases.
• Functional Independence: Strong muscles contribute to better balance, mobility, and the ability to perform daily activities, enhancing quality of life into older age.

You’ll see significant overlap with the work of:

Dr. Donald K. Layman

Dr. Donald K. Layman, Professor Emeritus of Nutrition at the University of Illinois, has extensively researched the role of dietary protein in muscle health, particularly in older adults. His work emphasizes the importance of protein intake and distribution in combating age-related muscle loss.

Key Insights from Dr. Layman’s Research:

Anabolic Resistance and Protein Needs
Dr. Layman notes that while a younger individual may respond robustly to a certain amount of protein, an older adult might exhibit only a 10% response or none at all. To mitigate this, he suggests:

• Higher Protein Intake: Older adults may require up to twice the standard Recommended Dietary Allowance (RDA) of protein, aiming for ~1.6 grams per kilogram of body weight daily.
• Leucine-Rich Proteins: Focusing on high-quality proteins rich in leucine—such as dairy, lean meats, and legumes—can stimulate muscle protein synthesis more effectively.

Protein Distribution and Meal Timing
Dr. Layman emphasizes the importance of distributing protein intake evenly across meals to maximize muscle protein synthesis. He recommends:

• Consistent Protein per Meal: Consuming about 30–40 grams of protein per meal, ensuring each meal contains sufficient leucine to trigger muscle-building pathways.
• Meal Timing: Aligning protein intake with physical activity, especially post-exercise, can enhance the anabolic response.

Role of Resistance Training
Combining increased protein intake with regular resistance exercise is crucial. Dr. Layman points out that resistance training acts synergistically with dietary protein to promote muscle maintenance and growth in older adults.

Muscle-Centric Health Approach
Beyond muscle maintenance, Dr. Layman advocates for a muscle-centric approach to overall health. He highlights that healthy muscle mass plays a vital role in:

• Metabolic Health: Muscles help regulate blood sugar, insulin sensitivity, and lipid profiles.
• Functional Independence: Maintaining muscle strength reduces the risk of falls and supports daily activities.

The P:E Ratio: Prioritizing Protein Over Energy

To address this, Dr. Naiman advocates for focusing on the Protein-to-Energy (P:E) ratio in foods. This ratio compares the amount of protein to the combined energy from fats and carbohydrates. By selecting foods with a higher P:E ratio, individuals can increase satiety and potentially reduce total calorie intake.

This approach encourages the consumption of nutrient-dense, protein-rich foods while minimizing intake of energy-dense, low-protein items.

Practical Implications

Dr. Naiman’s recommendations include:

• Increasing Protein Intake: Aim for a higher percentage of protein in the diet to enhance satiety.
• Choosing High P:E Ratio Foods: Select foods that provide more protein relative to their energy (caloric) content.
• Limiting Refined Carbohydrates and Fats: Reduce consumption of foods high in fats and sugars that offer little protein.

By aligning dietary choices with the body’s protein needs, individuals may find it easier to manage hunger and maintain a healthy body composition.

Naiman’s recent book Satiety Per Calorie contains seven pages of references for his protein recommendations and is inexpensive to download from his website, if you’re curious about this approach.

Research has consistently shown that, while those with compromised kidney function may need to be careful with protein, for individuals with normal kidney function, consuming higher amounts of protein does not lead to kidney damage.  Research links below, but two things of note:

1. Dr. Eric Westman is a physician and researcher specializing in the clinical application of low-carbohydrate and ketogenic diets. As an Associate Professor of Medicine at Duke University and director of the Duke Lifestyle Medicine Clinic, he has conducted extensive research on how carbohydrate restriction can improve metabolic health, particularly in individuals with obesity, type 2 diabetes, and cardiovascular risk factors.  He and Dr. David Unwin, another well-known physician using low-carb (and therefore higher-protein) diets to treat metabolic disease, have both had their programs audited.  Several hundred of their program participants with compromised renal function were tracked through their programs, and no further adverse effect on kidney function was observed.

2. Also worth noting is the fact that ongoing research into high-protein diets continues to be supported and published. If there were a strong consensus that these diets were harmful, we would not expect to see continued scientific interest or funding in this area.

Summary

• Healthy Individuals: High-protein diets do not impair kidney function in people without pre-existing kidney conditions.
• Physiological Adaptation: Increases in GFR (glomerular filtration rate) observed with higher protein intake are normal adaptations and not indicative of kidney damage.
• At-Risk Populations: Individuals with existing kidney disease should consult healthcare providers regarding protein intake, as different guidelines may apply.

In conclusion, for healthy individuals, consuming a high-protein diet is not associated with kidney harm. However, those with kidney disease or other health concerns should seek personalized medical advice.

• Dietary protein intake and renal function
• Changes in Kidney Function Do Not Differ between Healthy Adults Consuming Higher- Compared with Lower- or Normal-Protein Diets: A Systematic Review and Meta-Analysis
• A Systematic Review of Renal Health in Healthy Individuals Associated with Protein Intake above the US Recommended Daily Allowance in Randomized Controlled Trials and Observational Studies

THE TAKEAWAY

• Age-related muscle loss is not inevitable—resistance training and adequate protein can preserve and build muscle.
• High protein intake is not harmful for individuals with healthy kidneys, and even those with kidney concerns may benefit under medical guidance.
• Aiming for around 30 grams of protein at your first meal can help stimulate muscle growth and maintenance, especially in older adults.

• Breen, Leigh, et al. “Skeletal muscle protein metabolism in the elderly: Interventions to counteract the ‘anabolic resistance’ of ageing” Nutrition and Metabolism, (Lond) 8, 68 (2011). https://doi.org/10.1186/1743-7075-8-68.

• Morton, Robert W., et al. “Does protein supplementation really augment hypertrophy in older persons with resistance exercise training?.” The American Journal of Clinical Nutrition, Volume 107, Issue 6, 1054 – 1056.  https://ajcn.nutrition.org/article/S0002-9165(22)02889-1/fulltext.

• Layman, Donald K. “Dietary Guidelines should reflect new understandings about adult protein needs.” Nutrition & Metabolism 6, 12 (2009). https://doi.org/10.1186/1743-7075-6-12.

• Layman, Donald K., et al. “Dietary Protein Distribution Positively Influences 24-h Muscle Protein Synthesis in Healthy Adults.” Journal of Nutrition, 2014. https://doi.org/10.3945/jn.113.185280.

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