Science

Discussion of what drives us

  • Skeletal muscle is essential for metabolic health and physical function. With age, muscle mass and strength decline, increasing the risk of mobility issues, disease, and early mortality.

  • Starting around age 40, muscle mass (sarcopenia) decreases by ~0.8–1% per year, and strength/power (dynapenia) by ~2–3% per year. Older adults often consume less protein, due to changes in appetite, energy needs, and other factors.

  • Muscle mass is maintained by the balance of muscle protein synthesis (MPS) and breakdown (MPB). Resistance exercise (RE) and protein intake support muscle growth, but older adults experience "anabolic resistance," making it harder to maintain muscle. Nutritional strategies with higher protein intake can help.

  • Research shows older adults need >1.2 g/kg/day of protein to stimulate MPS. Studies found those consuming 1.5 g/kg/day had better muscle retention than those consuming the recommended 0.8 g/kg/day. Higher protein intake (>78.5 g/day) may also improve bone health and reduce fracture risk.

  • Higher daily protein intake has been linked to better physical function, fewer disabilities, and greater grip strength in older adults.

Protein Recommendations

Recommended Protein Intake by Age Group

Ages 40-49:
Protein Intake: 0.8 to 1.0 grams per kilogram (0.36 to 0.45 grams per pound) of body weight per day.
Rationale: In this decade, maintaining muscle mass and function becomes increasingly important as age-related muscle decline (sarcopenia) can begin. A moderate increase from the standard RDA is often recommended to support muscle maintenance and overall health.

Ages 50-59:
Protein Intake: 1.0 to 1.2 grams per kilogram (0.45 to 0.54 grams per pound) of body weight per day.
Rationale: The rate of muscle loss can accelerate during this period, so higher protein intake is recommended to help preserve muscle mass and strength.

Ages 60-69:
Protein Intake: 1.2 to 1.5 grams per kilogram (0.54 to 0.68 grams per pound) of body weight per day.
Rationale: During this decade, anabolic resistance increases, making it harder for the body to synthesize muscle protein. Higher protein intake, along with resistance exercise, is essential for maintaining muscle health.

Ages 70-79:
Protein Intake: 1.2 to 1.5 grams per kilogram (0.54 to 0.68 grams per pound) of body weight per day.
Rationale: Continued focus on preventing sarcopenia and frailty is critical. Adequate protein intake helps maintain muscle mass, strength, and function, which are key to preserving independence and reducing the risk of falls.

Ages 80+:
Protein Intake: 1.2 to 1.6 grams per kilogram (0.54 to 0.73 grams per pound) of body weight per day.
Rationale: In the oldest age group, the risk of muscle wasting (sarcopenia) is highest. Higher protein intake is recommended to support muscle preservation, enhance physical function, and improve overall health outcomes.

References:

  • Bauer, J., et al. (2013). Evidence-based recommendations for optimal dietary protein intake in older people: A position paper from the PROT-AGE Study Group. Journal of the American Medical Directors Association, 14(8), 542-559.
  • Deutz, N. E. P., et al. (2014). Protein intake and exercise for optimal muscle function with aging: Recommendations from the ESPEN Expert Group. Clinical Nutrition, 33(6), 929-936.
  • Mamerow, M. M., et al. (2014). Dietary protein distribution positively influences 24-h muscle protein synthesis in healthy adults. The Journal of Nutrition, 144(6), 876-880.
  • Morley, J. E., et al. (2010). Nutritional recommendations for the management of sarcopenia. Journal of the American Medical Directors Association, 11(6), 391-396.
  • Paddon-Jones, D., & Rasmussen, B. B. (2009). Dietary protein recommendations and the prevention of sarcopenia: Protein, aging, and physical activity. Current Opinion in Clinical Nutrition and Metabolic Care, 12(1), 86-90.