Animal proteins stimulate muscle protein synthesis (MPS) more effectively than plant proteins in older adults, while no major difference is observed in younger adults.

noli's read

This advice is based on the concept of 'anabolic resistance,' a well-documented phenomenon where the efficiency of protein synthesis decreases with age (Journal of the International Society of Sports Nutrition, review). Research indeed confirms that animal proteins, being often richer in leucine and having a more complete amino acid profile, are more effective at triggering the anabolic response in seniors (RCT studies). For younger adults, evidence suggests that with equivalent total protein and leucine amounts, the source (animal vs. plant) plays a less critical role, as the metabolism is more reactive (meta-analysis, Sports Medicine). Gabrielle Lyon correctly highlights this increased need for leucine in seniors to overcome this resistance. There is no exaggeration here, as she clearly distinguishes between the two populations. The argument is scientifically robust and aligned with the current consensus on muscle mass management during aging.

the sources

No named source held this one up — that absence is part of the verdict.