Protein Prescription for Aging Muscles: Why Leucine Matters More After 60

The Muscle-Building Supplements That ACTUALLY Work (YouTube link)

Muscle and bone health aren’t just parallel concerns—they’re mutually reinforcing systems. Protecting one helps preserve the other. That’s why interventions like resistance training, adequate protein (especially leucine), vitamin D, and mobility-focused exercise are central to healthy aging strategies.

Leucine: A Key to Combating Age-Related Muscle Loss 

Maintaining muscle mass is difficult as we age due to anabolic resistance, a reduced ability of aging muscle to respond to protein and exercise (Breen & Phillips, 2011). This resistance is a major factor in sarcopenia (age-related muscle loss).

To counter this, older adults need a higher protein intake (1.2–2.0 g/kg of body weight/day, compared to 0.8 g/kg for younger adults) and should aim for 25–40 grams of high-quality protein per meal (Deutz et al., 2014; Moore et al., 2015).

Leucine, a branched-chain amino acid, is the primary trigger for muscle protein synthesis (MPS). It activates the mTOR pathway, which is essential for muscle repair and growth (Anthony et al., 2000).

Crucially, older adults require a higher threshold of leucine to stimulate MPS and overcome anabolic resistance—often 2.5–3 grams per meal, compared to 1.7–2.4 grams for younger adults (Katsanos et al., 2006).

Therefore, focusing on leucine-rich protein sources is vital for older adults to prevent muscle loss, preserve functional independence, and maintain vitality (Moore et al., 2015).

Leucine and Protein Content by Food

Preserving muscle mass with age requires focusing on leucine, a key amino acid that drives muscle protein synthesis (MPS), especially as the body becomes less responsive to protein. Leucine content varies across foods, making strategic choices vital. This table presents leucine and total protein content to guide effective dietary planning for muscle health.

Food Source	Protein and Leucine Content	Additional Benefits	Practicality
Eggs	6 g protein, ~1.2 g leucine per large egg; 2 eggs (12 g protein, 2.4 g leucine) (USDA, 2023). High leucine (8.5%), complete protein.	Provides choline for brain health, vitamin D for bones, and B vitamins for energy metabolism. High bioavailability supports efficient muscle protein synthesis (MPS) (van Vliet et al., 2015).	Versatile (boiled, scrambled, omelets), quick to prepare, and widely available. May be limited by cholesterol concerns or allergies. Affordable but less nutrient-diverse than other sources.
Lentils	18 g protein, ~1.3 g leucine per cooked cup (USDA, 2023). Moderate leucine (7%), incomplete protein unless paired with grains (Young & Pellett, 1994).	Rich in fiber (15 g/cup) for digestion and blood sugar control, magnesium (50-100 mg) for muscle function, iron (2-4 mg) for oxygen delivery, and antioxidants (polyphenols) to reduce inflammation (Messina, 1999). Linked to reduced diabetes and heart disease risk (Bazzano et al., 2008).	Affordable, shelf-stable, and versatile (soups, salads, curries). Larger servings (~1.5-2 cups) needed for MPS due to lower leucine. May cause bloating in some; soaking reduces anti-nutrients.
Beans (e.g., Black Beans, Chickpeas)	15 g protein, ~1-1.2 g leucine per cooked cup (USDA, 2023). Moderate leucine (6-7%), incomplete protein unless combined with grains (Young & Pellett, 1994).	High in fiber (10-15 g/cup), magnesium (50-100 mg), iron (2-4 mg), and antioxidants, supporting digestion, metabolic health, and inflammation reduction (Anderson & Major, 2002). Supports muscle retention and cardiovascular health (Marventano et al., 2017).	Cost-effective, shelf-stable, and versatile (salads, stews, hummus). Requires larger portions or combinations for MPS. Digestive discomfort possible; preparation (soaking) enhances bioavailability.
Greek Yogurt	20 g protein, ~2 g leucine per 170 g (1 cup) (Phillips et al., 2016). High leucine (8-10%), complete protein with whey and casein.	Supplies calcium (200-300 mg) and vitamin D (fortified) for bone health and muscle contraction. Reduces fracture risk and supports sustained MPS (Holick, 2007; Yang et al., 2012).	Convenient for snacks or meals, pairs well with fruits/nuts. Ideal for reduced appetite in older adults. Limited by lactose intolerance or dairy allergies. Moderately priced.
Cottage Cheese	20 g protein, ~2.5 g leucine per 100 g (Phillips et al., 2016). High leucine (8-10%), complete protein with casein for slow-release MPS.	Provides calcium (200 mg) and vitamin D (fortified), supporting bones and muscles. Efficient for MPS, especially post-exercise (Yang et al., 2012).	Easy to eat (snacks, spreads), high protein in small volumes. Suitable for older adults. Dairy allergies or lactose issues may limit use. Affordable and widely available.
Chicken/Turkey (Lean)	30 g protein, ~2.5-3 g leucine per 100 g cooked (Churchward-Venne et al., 2014). High leucine (8-9%), complete protein, high bioavailability.	Rich in B vitamins (B12, niacin) for energy metabolism and iron for muscle oxygenation. Supports physical and cognitive function (Churchward-Venne et al., 2014).	Versatile (grilled, baked), widely available. Lean cuts reduce fat concerns. Preparation time and cost may be barriers; canned options less practical. Meets MPS threshold efficiently.
Fish (e.g., Salmon, Tuna)	25 g protein, ~2-2.5 g leucine per 100 g cooked (Churchward-Venne et al., 2014). High leucine (8%), complete protein.	Supplies omega-3 fatty acids (1-2 g/serving) to enhance MPS, reduce inflammation, and support brain/heart health. Rich in B12 and vitamin D (Smith et al., 2011).	Versatile (grilled, canned), but costlier than legumes. Canned fish (sardines, tuna) are affordable, convenient. High bioavailability, ideal for MPS. Mercury concerns in some fish (e.g., tuna).
Soy (Tofu, Tempeh)	15 g protein, ~1.5-2 g leucine per 100 g (Tang et al., 2009). High leucine (7-8%), complete protein, plant-based.	Provides magnesium, iron, and isoflavones for hormonal health. Comparable to animal proteins for MPS, supports muscle and metabolic health (Messina, 2016).	Versatile (stir-fries, grilling), suitable for vegetarians or egg-allergic individuals. Moderately priced, widely available. Smaller servings than animal proteins for MPS due to slightly lower leucine.
Quinoa	14 g protein, ~1 g leucine per cooked cup (USDA, 2023). Moderate leucine (7%), complete protein (van Vliet et al., 2015).	Offers magnesium and fiber for muscle and metabolic health. Supports digestion and nutrient diversity (Messina, 2016).	Versatile (salads, sides), but costlier than legumes. Larger servings or combinations needed for MPS due to lower leucine. Suitable for plant-based diets.
Nuts (e.g., Almonds)	6 g protein, ~0.5 g leucine per 30 g (Gorissen et al., 2018). Low leucine (5-6%), incomplete protein.	Provides healthy fats (monounsaturated), vitamin E, and magnesium, supporting metabolic health and inflammation reduction. Supplementary protein source (Gorissen et al., 2018).	Convenient as snacks, but calorie-dense (portion control needed). Not ideal for MPS alone due to low protein/leucine. Expensive compared to legumes.
Seeds (e.g., Pumpkin Seeds)	10 g protein, ~0.7 g leucine per 30 g (Gorissen et al., 2018). Low leucine (6%), incomplete protein.	Rich in omega-3s (e.g., chia/flaxseeds), magnesium, and antioxidants, supporting muscle and heart health. Supplementary source (Gorissen et al., 2018).	Easy to add to meals/snacks, but calorie-dense. Low leucine limits MPS efficacy. Cost varies; chia/flaxseeds pricier than legumes.
Beef Gelatin Powder	6-10 g protein, ~0.3-0.5 g leucine per 10-15 g (1 tbsp) (USDA, 2023). Low leucine (3-4%), incomplete protein (lacks tryptophan).	Supports joint and gut health via collagen-derived amino acids (glycine, proline). May reduce osteoarthritis pain and gut inflammation (Clark et al., 2008; Scaldaferri et al., 2017). Grass-fed sources may offer trace omega-3s.	Affordable, shelf-stable, easy to add to broths, smoothies, gummies. Requires leucine-rich pairing for MPS. Limited by low leucine and incomplete profile.
Hydrolyzed Collagen (Collagen Peptides)	8-10 g protein, ~0.3-0.4 g leucine per 10 g (1-2 tbsp) (Paul et al., 2019). Low leucine (3-4%), incomplete protein (lacks tryptophan).	Enhances joint health (reduces osteoarthritis pain), skin elasticity (~20% wrinkle reduction), and bone density. May aid muscle recovery with exercise, but less effective for MPS than whey (Moskowitz, 2000; Proksch et al., 2014; Zdzieblik et al., 2015).	Dissolves easily in hot/cold liquids (coffee, smoothies), tasteless, and versatile. Ideal for supplements. Must pair with leucine-rich sources for MPS. Moderately priced, widely available.
Whey Protein	20-25 g protein, ~2.7-3.5 g leucine per 25 g (1 scoop) (Tang et al., 2009; Devries & Phillips, 2015). High leucine (10-12%), complete protein, high bioavailability.	Rich in BCAAs and cysteine, supporting immune function and antioxidant production (glutathione). Highly effective for MPS, especially post-exercise, and supports muscle retention in aging (Yang et al., 2012; Devries & Phillips, 2015).	Convenient as a powder (smoothies, shakes), ideal for older adults with reduced appetite. Dissolves easily, widely available. May cause digestive issues in lactose-intolerant individuals. Moderately priced, but costlier than whole foods like legumes.

Notes 

• Protein and Leucine Content: Values are approximate, based on USDA FoodData Central (2023) and studies (e.g., van Vliet et al., 2015; Tang et al., 2009). Leucine content is critical for MPS, with 2.5-3 g per meal recommended for older adults (Moore et al., 2015).
• Additional Benefits: Focuses on nutrients beyond protein (e.g., fiber, omega-3s, calcium) that support muscle, bone, and overall health, with references to studies (e.g., Smith et al., 2011; Holick, 2007).
• Practicality: Considers ease of use, cost, availability, and dietary restrictions. Animal proteins are efficient for MPS, while plant proteins and collagen products offer affordability and versatility.
• Hydrolyzed Collagen: Included as it aligns with beef gelatin’s collagen-derived benefits but is more user-friendly (dissolves in cold liquids). Its low leucine limits MPS efficacy, similar to gelatin, but it complements other sources (Zdzieblik et al., 2015).
• Eggs: Added as a baseline. They are efficient for MPS but lack the broader nutrient profile of alternatives like legumes or fish.
• Essential amino acids: Which include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine, are amino acids that the human body cannot synthesize and must be obtained through the diet to support critical functions like protein synthesis and tissue repair.
• Creatine monohydrate (as shown in the video): A well-researched supplement, enhances muscle strength, power, and recovery by boosting ATP availability, improving high-intensity exercise performance and resistance training outcomes, which may indirectly support muscle protein synthesis (MPS) and benefit cognitive function in older adults (Kreider et al., 2017; Candow et al., 2023).

References

1. Breen & Phillips, 2011: Breen, L., & Phillips, S. M. (2011). Skeletal muscle protein metabolism in the elderly: Interventions to counter sarcopenia. Nutrition & Metabolism, 8, 68.
2. Deutz et al., 2014: Deutz, N. E., Bauer, J. M., Barazzoni, R., Biolo, G., Boirie, Y., Bosy-Westphal, A., ... & Calder, P. C. (2014). Protein intake and exercise for optimal muscle function with aging: Recommendations from the ESPEN Expert Group. Clinical Nutrition, 33(6), 929-936.
3. Moore et al., 2015: Moore, D. R., Churchward-Venne, T. A., Witard, O., Breen, L., Burd, N. A., Tipton, K. D., & Phillips, S. M. (2015). Protein ingestion to stimulate myofibrillar protein synthesis requires greater relative protein intakes in healthy older versus younger men. The Journal of Gerontology: Series A, 70(1), 57-62.
4. Anthony et al., 2000: Anthony, J. C., Anthony, T. G., Kimball, S. R., Vary, T. C., & Jefferson, L. S. (2000). Orally administered leucine stimulates protein synthesis in skeletal muscle of postabsorptive rats in association with increased eIF4F formation. The Journal of Nutrition, 130(2), 139-145.
5. Katsanos et al., 2006: Katsanos, C. S., Kobayashi, H., Sheffield-Moore, M., Aarsland, A., & Wolfe, R. R. (2006). A high proportion of leucine is required for optimal stimulation of the rate of muscle protein synthesis by essential amino acids in the elderly. American Journal of Physiology-Endocrinology and Metabolism, 291(2), E381-E387.
6. Young & Pellett, 1994: Young, V. R., & Pellett, P. L. (1994). Plant proteins in relation to human protein and amino acid nutrition. The American Journal of Clinical Nutrition, 59(5 Suppl), 1203S-1212S.
7. Phillips et al., 2016: Phillips, S. M., Chevalier, S., & Leidy, H. J. (2016). Protein “requirements” beyond the RDA: implications for optimizing health. Applied Physiology, Nutrition, and Metabolism, 41(5), 565-572.
8. Churchward-Venne et al., 2014: Churchward-Venne, T. A., Burd, N. A., & Phillips, S. M. (2014). Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to enhance anabolism. Nutrition & Metabolism, 9(1), 40.
9. Smith et al., 2011: Smith, G. I., Atherton, P., Reeds, D. N., Mohammed, B. S., Rankin, D., Rennie, M. J., & Mittendorfer, B. (2011). Omega-3 polyunsaturated fatty acids augment the muscle protein anabolic response to hyperinsulinaemia-hyperaminoacidaemia in healthy young and middle-aged men and women. Clinical Science (London, England), 121(6), 267-278.
10. Messina, 1999: Messina, M. J. (1999). Legumes and soybeans: overview of their nutritional profiles and health effects. The American Journal of Clinical Nutrition, 70(3 Suppl), 439S-450S.
11. Anderson & Major, 2002: Anderson, J. W., & Major, A. W. (2002). Pulses and lipaemia, short- and long-term effect: Potential in the prevention of cardiovascular disease. British Journal of Nutrition, 88(Suppl 3), S263-S271.
12. Bazzano et al., 2008: Bazzano, L. A., Thompson, A. M., Tees, M. T., Nguyen, C. H., & Winham, D. M. (2008). Non-soy legume consumption lowers cholesterol levels: A meta-analysis of randomized controlled trials. Nutrition, Metabolism, and Cardiovascular Diseases, 21(2), 94-103.
13. Marventano et al., 2017: Marventano, S., Izquierdo Pulido, M., Sánchez-González, C., Godos, J., Speciani, A., Galvano, F., & Grosso, G. (2017). Legume consumption and CVD risk: a systematic review and meta-analysis. Public Health Nutrition, 20(2), 245-254.
14. Tang et al., 2009: Tang, J. E., Moore, D. R., Kujbida, G. W., Tarnopolsky, M. A., & Phillips, S. M. (2009). Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. Journal of Applied Physiology, 107(3), 987-992.
15. Gorissen et al., 2018: Gorissen, S. H. M., Crombag, J. J. R., Senden, J. M. G., Waterval, W. A. H., Bierau, J., Verdijk, L. B., & van Loon, L. J. C. (2018). Protein content and amino acid composition of commercially available plant-based protein isolates. Amino Acids, 50(12), 1685-1695.
16. van Vliet et al., 2015: van Vliet, S., Burd, N. A., & van Loon, L. J. C. (2015). The skeletal muscle anabolic response to plant- versus animal-based protein consumption. The Journal of Nutrition, 145(9), 1981-1991.
17. Clark et al., 2008: Clark, K. L., Sebastianelli, W., Flechsenhar, K. R., Aukermann, D. F., Meza, F., Millard, R. L., ... & Albert, A. (2008). 24-Week study on the use of collagen hydrolysate as a dietary supplement in athletes with activity-related joint pain. Current Medical Research and Opinion, 24(5), 1485-1496.
18. Scaldaferri et al., 2017: Scaldaferri, F., Lopetuso, L. R., Petito, V., Cammarota, G., & Gasbarrini, A. (2017). Gelatin tannate as a new therapeutic option for acute diarrhea in children and adults: A systematic review. European Review for Medical and Pharmacological Sciences, 21(23), 5485-5491.
19. Moskowitz, 2000: Moskowitz, R. W. (2000). Role of collagen hydrolysate in bone and joint disease. Seminars in Arthritis and Rheumatism, 30(2), 87-99.
20. Bello & Oesser, 2006: Bello, A. E., & Oesser, S. (2006). Collagen hydrolysate for the treatment of osteoarthritis and other joint disorders: a review of the literature. Current Medical Research and Opinion, 22(11), 2221-2232.
21. Proksch et al., 2014: Proksch, E., Segger, D., Degwert, J., Schunck, M., Zague, V., & Oesser, S. (2014). Oral supplementation of specific collagen peptides has beneficial effects on human skin structure and function: a double-blind, placebo-controlled study. Skin Pharmacology and Physiology, 27(1), 47-55.
22. Zdzieblik et al., 2015: Zdzieblik, D., Oesser, S., Baumstark, M. W., Gollhofer, A., & König, D. (2015). Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men: a randomised controlled trial. British Journal of Nutrition, 114(8), 1237-1245.
23. Paul et al., 2019: Paul, C., Leser, S., & Oesser, S. (2019). Significant amounts of functional collagen peptides can be incorporated in the diet while maintaining indispensable amino acid balance. Nutrients, 11(5), 1079.
24. Devries & Phillips, 2015: Devries, M. C., & Phillips, S. M. (2015). Supplemental protein in support of muscle mass and health: advantage whey. Journal of Food Science, 80(S1), A8-A15.
25. Kreider et al., 2017: Kreider RB, Kalman DS, Antonio J, Ziegenfuss TN, Wildman R, Collins R, Candow DG, Kleiner SM, Almada AL, Lopez HL. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017 Jun 13; 14:18. 
26. Candow et al., 2023: Candow DG, Prokopidis K, Forbes SC, Rusterholz F, Campbell BI, Ostojic SM. Resistance Exercise and Creatine Supplementation on Fat Mass in Adults < 50 Years of Age: A Systematic Review and Meta-Analysis. Nutrients. 2023 Oct 12;15(20):4343. doi: 10.3390/nu15204343. 

Vegetarians: How to Get Enough Protein?

As a vegetarian, should you be concerned about protein deficiency?  The answer is probably NO for at least two reasons:

• People are actually more likely to suffer from protein excess than protein deficiency
• If you know what sources of plant protein to take 

How Much Protein Do You Really Need?

In [1], Dr. Michael Greger provides the following guidelines:

Adults require no more than 0.8 or 0.9 grams of protein per healthy kilogram of body weight per day, which is about your ideal weight in pounds multiplied by four and then divided by ten. So, someone whose ideal weight is 100 pounds may require up to 40 grams of protein a day. On average, they probably only need about 30 daily grams of protein, which is 0.66 grams per kilogram, but we round it up to 0.8 or 0.9 grams because everyone’s different and we want to capture most of the bell curve.

Adverse Effects of Protein Excess

People are actually more likely to suffer from protein excess than protein deficiency. “The adverse effects associated with long-term high protein/high meat intake” diets may include:^[1]

• Disorders of bone and calcium balance
• Disorders of kidney function
• Increased cancer risk
• Disorders of the liver
• Worsening of coronary artery disease

Considering all of these potential disease risks, there is currently no reasonable scientific basis to recommend protein consumption above the current recommended daily allowance.

Plant-Based Proteins

At Cleveland Clinic, it has pointed out the following 5 top sources of plant protein for your plant-based diet:^[2]

• Cooked Legumes
• 17g in 1 c.* lentils
• 16g in 1 c. chickpeas
• 12g in 1 c. black beans
• Soy
• 17g in 1 c. edamame
• 15g in 2 oz. tempeh
• 7g   in 3 oz. firm tofu
• Nuts and Seeds
• 9g in 1 oz. hemp seeds
• 8g in 1 oz. pumpkin seeds
• 7g in 2 T nut butters
• 6g in 1 oz. almonds
• 5g in 1 oz. chia seeds
• Cooked Grains
• 8g in 1 c. quinoa
• 4g in 1 c. oatmeal
• Cooked Vegetables
• 5g in 1 c. spinach
• 4g in 1 c. Brussels sprouts
• 2g in 1 c. broccoli

*: cooked cup (240 ml)

Complete Proteins

Did you know? Most plants are considered “incomplete proteins” because they lack some of the essential amino acids (total: 9). However, there are a few unique plants that are considered “complete proteins.” Listed below are plant-based foods that are considered complete proteins:

• AMARANTH:
• The highest source of iron among all gluten-free grains, amaranth is a complete protein and can be made into flour or toasted much like popcorn.
• QUINOA:
• An ancient cereal grain of Peru, quinoa cooks similar to rice but in half the time. This gluten-free grain contains healthy omega-3 and -6 fatty acids and is a complete protein.
• BUCKWHEAT:
• Buckwheat is actually a seed and not a grain. Unroasted buckwheat groats have a soft, mild flavor, while the roasted variety has an earthy, nutty flavor. A complete protein, the triangular seeds are frequently made into flour and is the primary ingredient in Japanese soba noodles.
• CHIA SEEDS:
• Chia seeds are complete proteins and the richest plant-based source of heart-healthy omega-3 fatty acids. Because chia seeds can absorb more than twelve times their weight in water, they are often used to add fluffiness in baked goods and are also used to replace eggs in vegan products.
• HEMP:
• A seed that can be eaten raw, ground into a meal or sprouted, Hemp contains omega-3s and is high in gamma linolenic acid (GLA), a healthy omega-6 fatty acid. This seed is a complete protein and can be easily made into a vegan milk by blending raw hemp seeds and filtered water.
• SOYBEANS:
• Soybeans (including edamame) and soy foods such as tofu, natto and tempeh are a complete protein. When choosing tofu, the firmer the tofu, the higher the protein content.
• SPIRULINA:
• Spirulina is a blue-green algae that grows in oceans and salty lakes in subtropical climates. A complete protein, spirulina is sold in supplement form and can help boost the growth of gut-friendly bacteria in the intestinal system.

Video 1. Increasing Protein Intake After Age 65 (YouTube link)

References

1. How Much Protein Do You Really Need?
2. Plant Proteins that Pack a Punch (Infographic)
3. The 17 Best Protein Sources For Vegans and Vegetarians
4. Plant Proteins that Pack a Punch (Infographic) 
5. 10 PLANT-BASED PROTEINS YOU SHOULD BE EATING
• 1 lentils, 2 hemp seeds, 3 chia seeds 4 quinoa 5 spirulina 6 nutritional yeast 7 seeds 8 nuts 9 beans 10 tempeh/organic tofu/edamame
6. Healthy Aging: Protein Consumption Advice for the Elderly (Travel to Health)
7. Study shows protein that reverses aging of skeletal muscle
8. Clean Protein or Toxic Blend? The Truth About Protein Powder