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Older Adults and Protein Intake: Prioritizing Muscle Health

Older Adults Have Higher Protein Requirements

In order to maintain muscle health as adults age, it is vital that older adults consume enough protein. But how much is enough? The current recommended daily allowance (RDA) for protein is 0.8 g/kg/day but this is likely inadequate to maintain muscle health as adults age [1,2]. Yet according to a study by Kerstetter et al. [3] it was reported that 32% to 41% of women and 22% to 38% of men beyond the age of 50 years failed to meet the RDA of 0.8 g/kg/day. Due to the sedentary lifestyles that many older adults live, they face the risk of muscle protein dyshomeostasis [1]. It is well understood that inflammation plays a major role in muscle loss [4,5] and unfortunately, many older adults suffer from conditions that are associated with an elevated inflammatory state such as obesity.

Figure 1: Protein intake requirements increase as adults age. Reproduced from [1].

Because of these three reasons (Figure 1), older adults have much higher protein requirements and it has been recommended that they consume between 1.0 – 1.5 g/kg/day of protein [6].

Spreading Protein Intake Out Throughout The Day To Maximize Muscle Protein Synthesis:

In 2014, Researchers at the University of Texas Medical Branch, Galveston conducted a randomized, 7-day crossover clinical study with a 30 day washout period to study the impact of protein intake distribution on mixed muscle protein fractional synthesis rate in adults between 25 to 55 years of age [7]. Their approach involved a stable-isotope labeling strategy and analysis of muscle biopsy samples. When subjects were in the EVEN phase of the study, they consumed ~30 grams of protein during breakfast, lunch and dinner. During the SKEW phase of the study, subjects consumed ~11 grams, ~16 grams and ~63 grams of protein for breakfast, lunch and dinner. It was demonstrated that the 24 hour rate of muscle protein synthesis was ~25% higher when protein was consumed evenly throughout the day rather than in a skewed pattern with the majority of protein being consumed at dinner (Figure 2).

Figure 2: 24-hour mixed muscle protein fractional synthesis rates (FSRs) in healthy adults on days 1 and 7 after consuming diets with an EVEN or SKEW protein intake distribution. Reproduced from [7].

Proteins Rich in Leucine Effectively Stimulate Muscle Protein Synthesis

A clinical study published in 2006 involving young and elderly men and women demonstrated that leucine is very effective in terms of stimulating muscle protein synthesis in elderly human subjects. Four groups of adults (2 elderly groups, 2 young groups) were studied before and after they were given 6.7 grams of essential amino acids (EAAs) that contained either 1.7 grams Leu (26% Leu) or 2.8 grams Leu (41% Leu). The results presented in Figure 3 clearly illustrate that increased consumption of leucine is very effective in terms of stimulating muscle protein synthesis, particularly for older adults.

Figure 3: Fractional synthetic rate of mixed muscle protein in the basal state (Basal) and after the ingestion of 6.7 g of EAA (Post-EAA) containing either 26% or 41% Leucine. Reproduced from [8].

Figure 4: Mixed muscle protein fractional synthetic rate (FSR) after ingestion of whey hydrolysate, casein, or soy protein at rest and after resistance exercise. Reproduced from [9].

Researchers at McMaster University, Canada studied the impact of essential amino acids (10 grams) given as either whey hydrolysate, micellar casein, or soy protein isolate in young healthy men after performing a bout of resistance training exercise [9]. It is evident that whey protein had a greater impact on stimulating muscle protein synthesis when compared with soy and casein (Figure 4). The authors suggested that these differences could be related to increased leucine content in whey protein along with differences in digestibility.

MYOS Physician Muscle Health Formula: Advanced Nutrition For Muscle Health

MYOS Physician Muscle Health Formula® is an advanced nutrition program comprised of Fortetropin®, natural vanilla flavor and dextrose.

Fortetropin® is an advanced nutrition product made from fertilized chicken egg yolk using a patented, low temperature manufacturing process [10,11] that helps to better retain the natural bioactivity of the proteins, peptides and lipids that are found to be present within fertilized, chicken egg yolk while destroying harmful pathogens. In human clinical studies, Fortetropin® has been shown to increase the rate of muscle protein synthesis [12] and lead to gains in muscle mass and strength [13]. A report that Fortetropin® reduces muscle disuse atrophy in dogs undergoing a common veterinary orthopedic procedure [14] inspired a human clinical trial on muscle disuse atrophy, initiated in early 2020.

A single serving of Fortetropin® contains very little protein – only 2 grams to be exact. Yet adding Fortetropin® to a healthy diet that provides enough protein can increase muscle protein synthesis in older adults (60-75 years old) by ~15%

Learn more about how Fortetropin®, the proprietary ingredient behind MYOS Physician Muscle Health Formula can help older adults improve their muscle health at


1. Landi, Francesco, et al. "Protein intake and muscle health in old age: from biological plausibility to clinical evidence." Nutrients 8.5 (2016): 295.

2. Wolfe, Robert R., and Sharon L. Miller. "The recommended dietary allowance of protein: a misunderstood concept." Jama 299.24 (2008): 2891-2893.

3. Kerstetter, Jane E., Kimberly O. O'Brien, and Karl L. Insogna. "Low protein intake: the impact on calcium and bone homeostasis in humans." The Journal of nutrition 133.3 (2003): 855S-861S.

4. Meng, Si-Jin, and Long-Jiang Yu. "Oxidative stress, molecular inflammation and sarcopenia." International journal of molecular sciences 11.4 (2010): 1509-1526.

5. Bano, Giulia, et al. "Inflammation and sarcopenia: A systematic review and meta-analysis." Maturitas 96 (2017): 10-15.

6. Morley, John E., et al. "Nutritional recommendations for the management of sarcopenia." Journal of the american Medical Directors association 11.6 (2010): 391-396.

7. Mamerow, Madonna M., et al. "Dietary protein distribution positively influences 24-h muscle protein synthesis in healthy adults." The Journal of nutrition 144.6 (2014): 876-880.

8. Katsanos, Christos S., et al. "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 (2006): E381-E387.

9. Tang, Jason E., et al. "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 (2009): 987-992.

10. Buxmann, Waldermar, et al. “Process for producing a composition for increasing muscle mass.” S. Patent # 10,165,785, Issue Date: January 1, 2019.

11. Buxmann, Waldermar, et al. “Process for producing a composition containing active follistatin.” S. Patent #8,815,320, Issue Date: August 26, 2014.

12.Evans, William J., et al. “Effects of Fortetropin® on the rate of muscle protein synthesis in older men and women: a randomized, double blinded, placebo-controlled study.” Gerontol Med Sci, submitted.

13. Sharp, Matthew H., et al. "The effects of fortetropin supplementation on body composition, strength, and power in humans and mechanism of action in a rodent model." Journal of the American College of Nutrition8 (2016): 679-691.

14. White, Dana A., et al. "Fortetropin inhibits disuse muscle atrophy in dogs after tibial plateau leveling osteotomy." Plos one 15.4 (2020): e0231306.

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