What does the evidence say about Protein Intake and Muscle?

The current Migaku evidence database contains 2 reusable source documents for Protein Intake and Muscle. This answer focuses on benefits, uncertainty, and practical interpretation. - 1 2 3 Frailty is a common geriatric syndrome characterised by increased vulnerability to stressors and a heightened risk of adverse health outcomes, including disability and higher rates of hospitalizations in older adults []. [Biersteker Esmée J.M. (2026); evidence level 2] - Although resistance training alone is beneficial, its effects may be further increased when protein intake is optimized [,,]. [Biersteker Esmée J.M. (2026); evidence level 2] - Importantly, evidence suggests that protein supplementation does not augment resistance training adaptations in older adults with adequate protein intake, whereas benefits appear primarily in those with low habitual intake [,,,,,,]. [Biersteker Esmée J.M. (2026); evidence level 2] - A major contributor to frailty is sarcopenia, defined as the progressive loss of skeletal muscle mass, muscle strength, and physical performance with aging [,]. [Biersteker Esmée J.M. (2026); evidence level 2] - In the prespecified overlap-weighted marginal structural model (ATO estimand), higher intake was associated with lower odds of mobility limitation, although the primary contrast comparing ≥ 1.2 versus Conclusions Higher usual protein intake was directionally associated with lower odds of mobility limitation among older U.S. [Ling Y (2026); evidence level 4] Evidence levels are sorting aids, not final clinical grades. Level 1 usually indicates systematic-review style evidence, level 2 indicates randomized trials or public-health guidance, and lower levels need more cautious wording. This page is educational. People with medical conditions, pregnancy, medication use, or unusual symptoms should ask a qualified clinician before changing supplements, medication, or treatment routines.