In plain terms

The claim being assessed: Increasing dietary protein intake above the adult recommended allowance improves physical performance in adults aged at least 60 years.

Where the evidence stands: Ε — Causal in a specific setting. It genuinely causes the effect in one well-defined situation, but that does not extend to the wider claim.

What this mechanism does: This makes the process worse or keeps it going, but something else starts it.

Strongest evidence for it: The registered primary-subclaim rule selects SC3. A quantified above-RDA protein contrast produced a modest functional benefit in a baseline malnourished, pre-frail or frail population. Controlled feeding and supplementation nulls in other defined populations limit generalization, supporting Ε with Moderate confidence. Acute synthesis and lean mass do not establish universal strength preservation. Weakest-link returns Γ; primary-subclaim and scope-matched return Ε. An open-label six-month dietary-advice trial (PROMISS, PMID 34609621) in non-malnourished community-dwelling adults with near-allowance habitual intake also improved its primary 400-m walk outcome, but it co-increased energy intake and lost significance per protocol, while OPTIMen was null at similar baseline intake, so reproducible intervention effects for Ζ are still not met.

What decisive evidence would look like

In plain terms, researchers would change the proposed cause, confirm it changed as intended, and measure a meaningful health outcome while checking other explanations. The result should be able to support or count against the claim.

Relative explanatory fit: Alternative ranked ahead

What this review means

Higher protein intake can improve selected muscle outcomes in some older adults - most clearly in nutritionally vulnerable groups, with one open-label trial also reporting a walking benefit in community-dwelling adults whose habitual intake was near the allowance; other controlled trials at similar intake find no benefit, and lean-mass changes do not establish stronger or more functional muscle.

Implications for health and treatment: The registered primary-subclaim rule selects SC3. A quantified above-RDA protein contrast produced a modest functional benefit in a baseline malnourished, pre-frail or frail population. Controlled feeding and supplementation nulls in other defined populations limit generalization, supporting Ε with Moderate confidence. Acute synthesis and lean mass do not establish universal strength preservation. Weakest-link returns Γ; primary-subclaim and scope-matched return Ε. An open-label six-month dietary-advice trial (PROMISS, PMID 34609621) in non-malnourished community-dwelling adults with near-allowance habitual intake also improved its primary 400-m walk outcome, but it co-increased energy intake and lost significance per protocol, while OPTIMen was null at similar baseline intake, so reproducible intervention effects for Ζ are still not met.

Limits for individual care: 57 primary reports with 5 selected partial-body examinations. Confidence is Moderate because the trials differ in formulation, achieved intake, comparator and endpoint, and positive and null results do not reproduce across baseline contexts; access depth is recorded separately and does not set the band. The grade applies to the exact registered claim; stronger findings for narrower subclaims remain separate. No complete-paper audit or blinded calibration is claimed. This educational review does not establish an individual treatment recommendation.

Medical information notice: This review provides general health information, not medical advice. It cannot diagnose a condition or replace an individual discussion with a qualified clinician.

Source checking used bounded original primary abstract passages/status records and selected original partial-body passages. No complete-abstract or complete-paper audit, or independent scientific peer review, is claimed. Detailed access counts and limitations appear in the review.

A low grade is not an accusation. It means the causal work has not been done yet, which is the ordinary state of most actively studied mechanisms in biology.

At a glance

Sub-claims assessed separately

Full assessment

From here the review is written for a technical reader: caps and thresholds, competing models, the independence basis, and the citation ledger.

Sources: 57 primary reports; claims: 62; verified: 62; unverified: 0. Verification is bounded attribution. Access: 5 partial-body and 52 bounded abstract/status examinations. Literature cutoff: 2026-10-12; source examination UTC date: 2026-10-13. No complete-paper audit or blinded calibration claimed.

Adversarial review: Authoring model of record: Sol 6.1 (this package's own review_metadata.reviewer and provenance_header.generated_by fields record "Codex; HSEF v5.3"; recorded, not edited). Adversarially reviewed by Claude Opus 5.5 (Anthropic) on 2026-10-14. 6 corrections applied (see ADVERSARIAL REVIEW AND APPROVAL). Status: Approved as revised. Round 3: independently re-reviewed by Claude Opus 5.5 (Anthropic) on 2026-11-02; 7 findings (P1-P7) applied, including the added PROMISS trial [57]; level and confidence unchanged (see ADVERSARIAL_REVIEW.protein-muscle-aging.md).

AT A GLANCE

Higher protein intake can improve selected muscle outcomes in some older adults - most clearly in nutritionally vulnerable groups, with one open-label trial also reporting a walking benefit in community-dwelling adults whose habitual intake was near the allowance; other controlled trials at similar intake find no benefit, and lean-mass changes do not establish stronger or more functional muscle.

Deciding experiment: A preregistered multicenter isocaloric protein quantity trial with 0.8 g/kg/day comparator and clearly achieved higher intake, stratified before outcomes by nutrition/frailty and including a factorial resistance-training component; GLP-1-treated adults need their own controlled stratum with measured function.

Belief versus evidence: The registered primary-subclaim rule selects SC3. A quantified above-RDA protein contrast produced a modest functional benefit in a baseline malnourished, pre-frail or frail population. Controlled feeding and supplementation nulls in other defined populations limit generalization, supporting Ε with Moderate confidence. Acute synthesis and lean mass do not establish universal strength preservation. Weakest-link returns Γ; primary-subclaim and scope-matched return Ε. An open-label six-month dietary-advice trial (PROMISS, PMID 34609621) in non-malnourished community-dwelling adults with near-allowance habitual intake also improved its primary 400-m walk outcome, but it co-increased energy intake and lost significance per protocol, while OPTIMen was null at similar baseline intake, so reproducible intervention effects for Ζ are still not met.

Best-supported rival: Mechanical loading is the main functional stimulus. PMID 33564844 separates protein-only from added loading in 208 healthy older adults over one year: whey/collagen alone are ineffective, heavy training with whey improves quadriceps and strength. It favors the loading/context model over a universal protein-only interpretation, without establishing the untested protein-versus-no-protein add-on within heavy training.

COMPETING MECHANISTIC MODELS

Rank 1: Mechanical loading is the main functional stimulus (Ε). Resistance exercise improves strength and muscle adaptation, while additional protein is a context-dependent modifier. PRO-Elderly and a healthy 24-week training study show exercise benefits with null protein add-ons, and CALM shows null protein-only arms alongside effective heavy loading; factorial studies separate some loading and nutrition effects. Positive nutrition-only trials show that training is not universally necessary for every functional benefit; CALM lacks a training-only arm and cannot quantify protein synergy.

Rank 2: Baseline malnutrition or energy deficit makes nutrition limiting (Ε). Correcting antecedent nutritional deficits produces selected benefits more often than increasing already adequate intake. Park dose trial in malnourished pre/frail elders and the nutrition-only Tieland functional trial retain positives; stable controlled-feeding nulls delimit transfer. Not all frail or malnourished trials are positive, and mixed energy/micronutrient supplements do not isolate protein quantity or a deterministic baseline-response rule. A pooled individual-participant analysis of nine RCTs in malnourished or at-risk older adults (PMID 37432139) found no overall effect of nutritional interventions on handgrip strength, and OPTIMen and PROMISS - with similar near-allowance habitual intake - point in opposite directions, so baseline nutritional status is not yet a validated responder rule.

Rank 3: Above-RDA protein improves older-adult strength or function (Ε). Raising dietary protein above 0.8 g/kg/day improves some clinical muscle outcomes in older adults. The 12-week 0.8/1.2/1.5 g/kg trial provides a direct dose contrast with gait benefit in a predefined vulnerable context. The OPTIMen direct 0.8 vs 1.3 g/kg functional null and longer supplementation nulls oppose broad generality; components and achieved intake are frequently unclear.

Rank 4: Anabolic or lean-tissue movement can occur without functional gain (Γ). Nutrient exposure changes acute MPS or lean tissue while clinical strength/function remains unchanged. Verreijen 2015 and bed-rest leucine studies show mass preservation with functional nulls, while tracer studies measure acute anabolism. Tieland shows functional benefit without mass gain, and Park shows both in its context; dissociation is real but not an all-purpose explanation of every trial.

The tournament does not alter the nominal level. Compatible pathways and flexible alternatives are not automatically proved by explaining observations.

FULL REVIEW

Registered claim and scope

Increasing dietary protein intake above the adult recommended allowance improves muscle strength or physical function in adults aged 60 years or older.

Evaluated wording: Increasing dietary protein intake above the adult recommended allowance improves physical performance in adults aged at least 60 years. The original wording names strength or physical function. Physical performance is a grammatical umbrella for those registered clinical outcomes; it does not admit tracer synthesis or DXA mass as a functional crossing. The above-0.8 g/kg/day contrast, baseline eligibility and 8–52-week horizon remain unchanged.

The nominal is the clinical sufficiency proposition represented by SC3. Mechanism, superiority, additional indication and safety subclaims are separately reported and do not gate the registered efficacy claim. The original topic family and this narrower gradeable restatement are retained; no response-based exclusions are allowed.

Selection: position 5 among the first five editorial traffic-priority families, registered on 2026-10-12. First five editorial traffic-priority families in health_topic_traffic_priority_2026-10-12/ranking.json; traffic proxies are not measured worldwide popularity or a preassigned verdict. Registered claim assessed against original sources; no independent blinded calibration is claimed.

Evidence and causal interpretation

Rubric fit: The shipped metabolism/aging rubric does not directly cover a clinical dietary-protein strength/function claim. Its explicit adaptation treats a credible randomized dietary quantity contrast affecting predefined muscle strength or physical function as a field-valid clinical perturbation; it does not demand lifespan extension. The ladder and six universal caps remain frozen. Acute MPS, nitrogen balance, lean tissue, anatomical muscle and physical function are separately interpreted; anabolic biomarkers never automatically validate the registered clinical phenotype.

The 57 examined original reports cover clinical nutrition, functional and body composition trials, acute tracer physiology, and explicit baseline, disease and exercise boundaries. They are not 57 trials of protein quantity alone. Five papers have selected Methods/Results verification, including original public PMC HTML when efetch returned no body; entire articles and supplements were not audited.

Park 2018 (PMID 30475969) directly compares 0.8, 1.2 and 1.5 g/kg/day in 120 malnourished prefrail or frail adults aged 70–85 over 12 weeks. The highest intake has small mass and gait advantages, while the intermediate arm is null. Tieland 2012 nutrition-only (PMID 22889730) reports SPPB improvement in 65 frail elders without mass gain; the strength difference is only a trend and achieved total intake is not verified in the original abstract. Its separate training trial (PMID 22770932, 62 participants, NCT01110369) augments lean mass but not strength or SPPB. These are distinct trials, rather than contradictory reports from one cohort.

OPTIMen 2018 (PMID 29532075) is an important counterexample. In functionally limited older men, increasing protein in controlled feeding produced no advantage in measured physical function. Body mass changes and drug effects were separately analyzed. This does not erase benefits in malnourished frail populations, but it tests a credible alternative to the assertion that every older adult needs more protein.

PROMISS 2021 (PMID 34609621, reference 57; added on 2 November 2026 after adversarial review) points the other way at a similar baseline. In 276 community-dwelling adults aged 65 or over whose habitual intake was below 1.0 g/kg adjusted body weight/day, six months of dietary advice plus protein-enriched foods targeting at least 1.2 g/kg/day improved the primary 400-m walk time by 12.4 s (95% CI 2.9 to 21.8 s) and leg-extension strength by 32.6 N versus no advice. The trial was open-label, the control arm received no advice, energy intake also rose by 107 kcal/day, only 37.5% of the advice arm reached the target, the per-protocol walk-time effect was not significant, and the advice-plus-timing arm (-4.9 s) had a confidence interval crossing zero. It is a functional-primary positive outside malnourished frailty, but not a blinded, isolated protein-quantity contrast, and OPTIMen remains null at similar baseline intake.

CALM 2021 (PMID 33564844) finds no protein-only benefit over one year, while heavy training with whey improves quadriceps and strength. Its missing training-only arm means it does not establish that whey augments heavy training. PRO-Elderly 2021 (PMID 34358827) and a 24-week healthy training trial (PMID 22968306) also find no supplementation add-on. Exercise benefit must be retained and attributed correctly.

PROVIDE 2015 (PMID 26170041) is often compressed into a positive protein trial, but both primary handgrip and SPPB between-arm effects were null. Secondary chair-rise and appendicular lean-tissue positives remain real, with vitamin D, leucine and whey bundled. Its safety follow-up (PMID 32162241) is not a new independent efficacy trial. Other enriched rehabilitation formulations produce positive functional outcomes, with their mixtures, baseline illness and variable 4–8-week discharge horizon retained.

Acute synthesis and body composition can diverge from function. Meal and amino-acid tracer studies (PMID 37972895, PMID 16507602) show composition-sensitive synthesis. Verreijen 2015 (PMID 25646324) preserves appendicular lean mass during weight loss and matched training without a between-arm strength or function benefit. Bed-rest leucine (PMID 32191600) partially preserves leg lean mass without preserving function. Conversely, Tieland nutrition-only improves function without mass gain. These dissociations make lean-mass loss alone an inadequate definition of sarcopenia or clinically important drug-related muscle harm.

The original 2017 weight-loss factorial body (PMID 28166780) finds no fat-free-mass protein main or interaction effect, but reports secondary protein-by-exercise interactions for grip and short gait. Actual intake separation is smaller than the prescribed targets and adjusted weight differs from measured body weight. Its reported complexity is retained: positive change within one arm is not evidence of a protein main effect.

Collagen 2015 (PMID 26353786) reports positive fat-free mass and strength with matched training, but uses a silica placebo and has a 2025 corrigendum (PMID 40859798) and critical comment (PMID 27267663) attached. Correction contents were unavailable in this retrieval, so no retraction or specific data error is invented. This report does not carry the clean clinical crossing. OPEN (PMID 32471657) has a null main functional result and post-randomization adherence subgroup signals; its caregiver-time analysis (PMID 41690799) remains the same cohort. LEAN-PREP can identify a pending research question, but its protocol does not supply a completed GLP-1 muscle-preservation result.

HYPOTHESIS STATE EVALUATION FRAMEWORK (HSEF v5.3)

Subclaim matrix and aggregation

Preregistered aggregation: primary-subclaim. The registered primary-subclaim rule selects SC3. A quantified above-RDA protein contrast produced a modest functional benefit in a baseline malnourished, pre-frail or frail population. Controlled feeding and supplementation nulls in other defined populations limit generalization, supporting Ε with Moderate confidence. Acute synthesis and lean mass do not establish universal strength preservation. Weakest-link returns Γ; primary-subclaim and scope-matched return Ε. An open-label six-month dietary-advice trial (PROMISS, PMID 34609621) in non-malnourished community-dwelling adults with near-allowance habitual intake also improved its primary 400-m walk outcome, but it co-increased energy intake and lost significance per protocol, while OPTIMen was null at similar baseline intake, so reproducible intervention effects for Ζ are still not met. Sensitivities: weakest-link Γ; primary-subclaim Ε; scope-matched Ε.

Decisive-perturbation inventory and causal tally

[1] 208-adult one-year randomized study finds whey/collagen alone ineffective while heavy training improves quadriceps and strength No training-only arm isolates protein add-on; baseline adequate-intake healthy adults not all frail contexts

[2] 200-person pre/frail trial finds whey soy leucine or creatine do not enhance training adaptations Shared training stimulus; baseline intake and adherence matter; no denial of exercise effect

[3] PROVIDE 380 has null between-arm handgrip/SPPB primary outcomes but positive secondary chair-rise and DXA lean mass Whey/leucine/vitamin D bundled; secondary multiplicity; lean tissue not strength; no isolated total protein claim

[14] Weight-loss factorial study finds no protein main mass effect but selected grip/gait protein-training interactions Actual intake contrast 1.13 vs 0.98 adjusted g/kg below prescribed separation; ages ≥55; secondary interaction multiplicity

[22] 120 malnourished pre-frail or frail elders randomized 0.8/1.2/1.5 g/kg for 12 weeks show 1.5-arm mass/gait improvement Primary mass not gait; modest secondary effect; 1.2-arm null; findings restricted to malnutrition/frailty

[28] 218 older sarcopenic adults 12-month whey trial finds no functional, grip or mass benefit or post-trial survival difference Home-exercise advice and gastrointestinal burden; baseline context not all underfed frailty

[53] OPTIMen 92 controlled 0.8 vs 1.3 g/kg six-month trial has null mass, strength, power and physical function Men only medically stable selected function limitations; limited precision for small benefit and no exercise stimulation

[54] Frail 65-person 24-week protein only trial reports SPPB improvement without muscle mass increase Leg extension between-arm trend not conventional significance; actual total dose not verified original abstract; not universal benefit

Tally: 1 positive qualifying study units across scoped subclaims; 24 screened discriminating contrast units. These are not independent causal lines or proof of full-claim necessity/sufficiency. Null and negative contrasts are discriminators, not positive threshold crossings. Reports and replications are not independent causal lines. Only positive same-scope protein quantity-functional contrasts earn primary crossing credit; multi-ingredient packages cannot manufacture pure protein effects. Acute MPS/IAAO, short bed rest, mixed age, sub-8-week rehab and >52-week follow-up support boundaries not the exact primary clinical horizon. Corrected collagen result remains bounded and not a load-bearing clinical crossing until notice contents and protein exposure attribution are clear. One parent study can produce legitimate secondary reports without adding an independent causal line.

Cap audit, precedence and Β/Γ/Δ boundary

Controlled human gait/strength outcomes cross the adapted clinical threshold for the precise baseline nutrition and dose context tested. Acute MPS and peripheral markers remain biomarker-limited evidence, and body composition surrogates do not replace function. Short rehabilitation, mixed age and multi-ingredient/combined training exposures retain their own scope; no effect attributed to an entire package is silently reassigned to protein alone.

Universal six-cap audit: All six universal caps were considered: cell-only inference, unperturbed association, ectopic expression, biomarker-only intervention, forced transfer/seeding, and inherited-to-sporadic scope transfer. Each binds its offered inference; complementary same-scope causal classes are assessed together rather than re-capped in isolation.

Gamma hard-rule audit: ROS, NAD and senescence-marker-only rules are not the basis for the clinical grade. MPS/IAAO and peripheral energetic biomarkers remain physiological endpoints; their downstream functional inference triggers the biomarker-only hard rule. Human randomized strength/function trials are scored within their clinical scope; the single-species animal-generalization rule is not used to cap directly observed human clinical interventions at Γ. Bundled supplements, open-label diet advice, post-randomization adherence and within-arm gains do not isolate a protein quantity effect.

SC1 cap: “Biomarker change without functional/phenotypic change caps at Γ.” Controlled feeding and tracer studies show acute anabolic responses that vary by dose, composition, activity and health. MPS or nitrogen-turnover movement alone does not demonstrate sustained muscle accretion or functional benefit, and nutrient-sensing mediation is not isolated. The functional inference from acute synthesis evidence is held at Γ under the biomarker-only cap.

SC1 field-valid definition: Literal shipped metabolism/aging rubric text (lifespan/healthspan wording); the applied clinical adaptation is stated below: “ - Genetic or pharmacologic intervention producing reproducible lifespan/healthspan extension - Must separate developmental effects from true aging effects - Biomarker change alone does NOT satisfy this threshold” Positive full-scope result: no. Controlled feeding and tracer studies show acute anabolic responses that vary by dose, composition, activity and health. MPS or nitrogen-turnover movement alone does not demonstrate sustained muscle accretion or functional benefit, and nutrient-sensing mediation is not isolated. The functional inference from acute synthesis evidence is held at Γ under the biomarker-only cap.

SC2 field-valid definition: Literal shipped metabolism/aging rubric text (lifespan/healthspan wording); the applied clinical adaptation is stated below: “ - Genetic or pharmacologic intervention producing reproducible lifespan/healthspan extension - Must separate developmental effects from true aging effects - Biomarker change alone does NOT satisfy this threshold” Positive full-scope result: yes. Controlled older-adult nutrition studies retain positive mass/lean-tissue findings in predefined malnourished, sarcopenic or energy-deficit contexts. Other controlled trials find no mass benefit despite higher intake; DXA/BIA lean tissue is not equivalent to anatomical muscle or strength. Context-specific preservation is Ε, with source-specific body composition limits and no inference that every higher protein protocol increases muscle.

SC3 field-valid definition: Literal shipped metabolism/aging rubric text (lifespan/healthspan wording); the applied clinical adaptation is stated below: “ - Genetic or pharmacologic intervention producing reproducible lifespan/healthspan extension - Must separate developmental effects from true aging effects - Biomarker change alone does NOT satisfy this threshold” Positive full-scope result: yes. A quantified 0.8/1.2/1.5 g/kg trial in baseline malnourished pre-frail or frail elders shows a modest gait benefit at 1.5 g/kg over 12 weeks, with the intermediate arm null. A frail protein-only 24-week trial also reports SPPB benefit while mass is unchanged, though its exact total dose is not verified in the original abstract. Controlled 0.8 vs 1.3 g/kg feeding in stable function-limited men and one-year sarcopenia trials are null. An open-label six-month advice-plus-protein-enriched-foods trial in non-malnourished community-dwelling adults with habitual intake below 1.0 g/kg adjusted body weight/day also reports a primary 400-m walk benefit, with energy intake co-increased and the per-protocol effect not significant. These map context-specific human functional causality at Ε; multi-ingredient/RT package successes cannot supply a universal protein effect.

SC4 field-valid definition: Literal shipped metabolism/aging rubric text (lifespan/healthspan wording); the applied clinical adaptation is stated below: “ - Genetic or pharmacologic intervention producing reproducible lifespan/healthspan extension - Must separate developmental effects from true aging effects - Biomarker change alone does NOT satisfy this threshold” Positive full-scope result: no. General efficacy across adequate intake, frailty and medication-assisted weight loss without training is not established. Predefined nutrition, training, formulation and energy balance modify outcomes; some frail cohorts are null. The GLP-1 lean-mass protection claim needs direct protein/training results rather than DXA loss narratives. Partial physiological plausibility remains Γ, not a validated generalization rule or a blanket claim that every older person needs the same high dose.

SC1 applied rubric adaptation (distinct from the unchanged literal criterion): Applied criterion: controlled nutrient delivery changes tracer-measured muscle protein synthesis. This demonstrates acute physiological response; extension to chronic muscle function retains the biomarker-only ceiling until matched functional evidence and mechanism specificity are present.

SC2 applied rubric adaptation (distinct from the unchanged literal criterion): Applied criterion: controlled quantity/quality exposure changes tissue-specific muscle size or appendicular lean tissue over a predefined interval, with hydration/measurement limits and clinical function reported separately. DXA or BIA is labeled as a proxy rather than histological muscle.

SC3 applied rubric adaptation (distinct from the unchanged literal criterion): Applied criterion: a credible randomized protein quantity contrast above 0.8 g/kg/day changes prespecified strength or physical function in baseline-defined ≥60-year adults over 8–52 weeks. Matched calories, co-ingredients and exercise components determine attribution.

SC4 applied rubric adaptation (distinct from the unchanged literal criterion): Applied criterion: prospectively measured baseline strata and factorial protein/training contrasts or medication-specific trials, with achieved intake and functional outcomes. Responder/adherence selection and cross-trial impressions do not establish generalized efficacy.

SC1 literal Γ hard rule: “ROS change measurements alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC1 literal Γ hard rule: “NAD level change measurements alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC1 literal Γ hard rule: “Mitochondrial metrics alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC1 literal Γ hard rule: “Senescence marker changes alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC1 literal Γ hard rule: “Single-species or single-strain evidence” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC1 literal Γ hard rule: “Biomarker-only improvement without organismal benefit” triggered for downstream functional inference from acute MPS/IAAO-only evidence

SC2 literal Γ hard rule: “ROS change measurements alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC2 literal Γ hard rule: “NAD level change measurements alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC2 literal Γ hard rule: “Mitochondrial metrics alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC2 literal Γ hard rule: “Senescence marker changes alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC2 literal Γ hard rule: “Single-species or single-strain evidence” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC2 literal Γ hard rule: “Biomarker-only improvement without organismal benefit” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC3 literal Γ hard rule: “ROS change measurements alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC3 literal Γ hard rule: “NAD level change measurements alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC3 literal Γ hard rule: “Mitochondrial metrics alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC3 literal Γ hard rule: “Senescence marker changes alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC3 literal Γ hard rule: “Single-species or single-strain evidence” not an animal-to-human generalization inference; registered human clinical intervention scope is directly tested

SC3 literal Γ hard rule: “Biomarker-only improvement without organismal benefit” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC4 literal Γ hard rule: “ROS change measurements alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC4 literal Γ hard rule: “NAD level change measurements alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC4 literal Γ hard rule: “Mitochondrial metrics alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC4 literal Γ hard rule: “Senescence marker changes alone” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC4 literal Γ hard rule: “Single-species or single-strain evidence” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

SC4 literal Γ hard rule: “Biomarker-only improvement without organismal benefit” Not triggered literally for this assembled scoped case. Any adapted clinical, proxy or system-inference restriction is stated separately in the subclaim rationale.

Upward threshold ladder

SC1 Δ: Literal shipped metabolism/aging rubric text (lifespan/healthspan wording); the applied clinical adaptation is stated in the applied rubric adaptation lines above: “Requires at least one intervention changing lifespan or healthspan in a way consistent with the hypothesis.” Satisfied: no. Pair sustained protein quantity exposure and integrated MPS/turnover with imaging and prespecified strength/function; demonstrate a mediation or dissociation test rather than declaring the acute rate increase sufficient.

SC2 Δ: Literal shipped metabolism/aging rubric text (lifespan/healthspan wording); the applied clinical adaptation is stated in the applied rubric adaptation lines above: “Requires at least one intervention changing lifespan or healthspan in a way consistent with the hypothesis.” Satisfied: yes. [22] 0.8/1.2/1.5 g/kg trial in 120 malnourished pre-frail or frail adults: 1.5 g/kg increased appendicular skeletal muscle mass versus 0.8 g/kg over 12 weeks (0.52 vs 0.08 kg, P = 0.036), the trial's primary endpoint, measured by DXA; the 1.2 g/kg arm was null.

SC2 Ε: “Requires causal effect in constrained contexts, backgrounds, or species.” Satisfied: yes. [22] 0.8/1.2/1.5 g/kg trial in 120 malnourished pre-frail or frail adults: 1.5 g/kg increased appendicular skeletal muscle mass versus 0.8 g/kg over 12 weeks (0.52 vs 0.08 kg, P = 0.036), the trial's primary endpoint, measured by DXA; the 1.2 g/kg arm was null.

SC2 Ζ: “Requires: - Reproducible intervention effects - Mechanistic narrowing - Evidence not reducible to general sickness, caloric reduction, or developmental artifacts” Satisfied: no. Replicate sustained anatomical muscle preservation with absolute baseline and achieved intake, matched energy, hydration controls and relevant exercise strata, rather than equating every DXA/BIA change with muscle gain.

SC3 Δ: Literal shipped metabolism/aging rubric text (lifespan/healthspan wording); the applied clinical adaptation is stated in the applied rubric adaptation lines above: “Requires at least one intervention changing lifespan or healthspan in a way consistent with the hypothesis.” Satisfied: yes. [22] 0.8/1.2/1.5 g/kg trial in 120 malnourished pre-frail or frail adults: 1.5 g/kg improved gait speed versus 0.8 g/kg (0.09 vs 0.04 m/s, P = 0.039), a secondary endpoint in a trial powered on appendicular muscle mass; the 1.2 g/kg arm was null.

SC3 Ε: “Requires causal effect in constrained contexts, backgrounds, or species.” Satisfied: yes. [22] 0.8/1.2/1.5 g/kg trial in 120 malnourished pre-frail or frail adults: 1.5 g/kg improved gait speed versus 0.8 g/kg (0.09 vs 0.04 m/s, P = 0.039), a secondary endpoint in a trial powered on appendicular muscle mass; the 1.2 g/kg arm was null.

SC3 Ζ: “Requires: - Reproducible intervention effects - Mechanistic narrowing - Evidence not reducible to general sickness, caloric reduction, or developmental artifacts” Satisfied: no. Run an adequately powered independently replicated isocaloric 0.8-versus-higher protein trial in prespecified frail/malnourished and adequately nourished adults with functional primary endpoints, matched co-ingredients and factorial training.

SC4 Δ: Literal shipped metabolism/aging rubric text (lifespan/healthspan wording); the applied clinical adaptation is stated in the applied rubric adaptation lines above: “Requires at least one intervention changing lifespan or healthspan in a way consistent with the hypothesis.” Satisfied: no. Test baseline intake/frailty/renal status and medication-assisted weight loss prospectively with direct dose separation, factorial exercise and clinically meaningful function, not post-outcome responder narrowing.

Upper ladder: Direct graded intake, factorial training, bed rest/de-training, tracer physiology and population diet studies were considered. They answer different endpoints/scopes. Replicated oral nutrition trials remain one clinical modality, observational diet cannot fix confounding, and MPS is not an orthogonal functional causal line. No validated baseline prediction, isolated nutrient mechanism or cross-context necessity/sufficiency supports Ζ or higher for the registered above-RDA function claim.

Independence: Complementary checks exclude different errors, but cannot be combined as independent positive lines for the same complete claim. Tracer physiology, chronic function and cross-sectional diet are not interchangeable evidence classes. PROVIDE follow-up is one parent study; OPEN caregiver-time analysis is one OPEN cohort; retrospective/subgroup reports preserve parent grouping.

Randomized dietary protein dose [22, 53]: Direct dose and energy controls reduce habitual diet selection; outcomes differ by baseline context, preventing universal causality.

Mechanical loading contrasts [1, 42, 2]: Training-versus-nutrition designs test the assumption that package benefit comes from protein; they do not form a second positive dietary protein line.

Tracer/disuse and endpoint dissociation [19, 21, 49, 55]: Biopsy/kinetic and bed rest tests detect anabolism and mass/function separation by different readouts, but do not prove the primary chronic above-RDA functional claim.

Falsification and pitfalls

Confirmation by biomarker. MPS, nitrogen balance, creatinine and DXA/BIA proxies are distinct from clinical strength/function.

Therapeutic effect misread as mechanistic proof. Multi-ingredient or training-package benefit does not isolate protein quantity or MPS mediation.

Scope fitted to the result. OPEN post-randomization adherence and retrospective responder groups cannot define who needs protein.

Negative field-valid perturbation read as a crossed threshold. OPTIMen/CALM/sarcopenia nulls are discriminators, not positive crossings.

Replication confused with reproduction. PROVIDE/OPEN secondary reports and pooled tracers are grouped by study; total reference count does not measure independent causal lines.

Adversarial steelman: above, then below

Case for Ζ: many randomized human nutrition studies report mass/grip/gait improvements, acute tracers show biological activity, and loading/protein factorial studies supply additional causal controls. This is stronger than a generic supplement story and includes real functionally relevant positive results.

Case for Δ: the clean above-RDA clinical dose positive rests heavily on one malnourished frail trial with secondary gait outcome, whereas large/long stable feeding and sarcopenia trials are null. Ingredient mixtures, inadequate dose separation and shared parent reports make the apparent replication volume much less direct than the bibliography suggests.

Ζ is rejected because nutrition RCT replication is one modality and mixed ingredient/tracer/loading experiments do not supply independent same-scope positive protein-function lines. Δ would understate the prospectively defined nutritional/dose boundary and positive-versus-null controlled context mapping; Ε retains restricted benefit without claiming a validated uniform response rule.

Final score, causal direction and M/S/D

The registered primary-subclaim rule selects SC3. A quantified above-RDA protein contrast produced a modest functional benefit in a baseline malnourished, pre-frail or frail population. Controlled feeding and supplementation nulls in other defined populations limit generalization, supporting Ε with Moderate confidence. Acute synthesis and lean mass do not establish universal strength preservation. Weakest-link returns Γ; primary-subclaim and scope-matched return Ε. An open-label six-month dietary-advice trial (PROMISS, PMID 34609621) in non-malnourished community-dwelling adults with near-allowance habitual intake also improved its primary 400-m walk outcome, but it co-increased energy intake and lost significance per protocol, while OPTIMen was null at similar baseline intake, so reproducible intervention effects for Ζ are still not met.

Above-RDA intake precedes selected functional gains in nutritionally vulnerable settings, so the intervention is not mere co-occurrence. Necessity of above-RDA intake for all older-adult strength, initiation and rate limitation are not established, and normal protein need must not be conflated with necessity of additional supplementation. Step 5 identifies a reinforcing/stabilizing input within a system also determined by loading, energy, health and neuromuscular adaptation.

Momentum: Mechanistic only. No examined work could cross the next threshold for the registered claim. The registered 2026 LEAN-PREP protocol PMID 42020128 is live work - it explicitly plans protein and resistance training during semaglutide/tirzepatide treatment, and no result from it is claimed - but it tests the medication-assisted weight-loss boundary that SC4 scopes, and under the pre-registered primary-subclaim rule a result there cannot move SC3, which sets the headline. Running is necessary but not sufficient: both halves of the definition have to hold, so this is active work on a neighbouring subclaim's boundary rather than momentum on the registered claim (lead adjudication, 2026-10-14). The recent factorial-target and nutrition-only reports PMID 42735207 and PMID 41805014 are completed, published trials and are evidence in the ledger above, not momentum. Active mechanistic and clinical work continues on protein dose, formulation and loading interactions without addressing the SC3 boundary check.

Stability: Stable. No named pending result could move the registered claim's letter. Completed LEAN-PREP functional and body-composition results could clarify the medication-assisted weight-loss context - precise functional nulls would narrow that application while positive controlled component effects could extend it - and no result from the protocol is claimed; but that trigger is scoped to that application and to SC4, not to the registered SC3 letter, and under the pre-registered primary-subclaim rule a result there cannot move the score. It is the only named pending result in this review: every trial registry identifier cited above belongs to a completed, published study already in the ledger, and the knowledge gaps and boundary experiment below name work that is needed but not under way, which is not a trigger. The framework's rule therefore applies - where no trigger that could move the score can be named, the answer is Stable by definition (lead adjudication, 2026-10-14). See the note on Stability in ADVERSARIAL REVIEW AND APPROVAL.

Divergence: Contested. The field is split in the artifacts examined here: supplementation and multi-ingredient rehabilitation trials are framed as showing that older adults need protein above the RDA, while the controlled-feeding and long-duration trials in the same evidence base (OPTIMen, CALM, the 12-month sarcopenia trial) report nulls and their authors frame the RDA as sufficient. No single field-implied level is defensible across those two framings, so no implied level and no arithmetic gap are manufactured. These dimensions do not change level or confidence.

PROPOSED DECISIVE EXPERIMENTS

A preregistered multicenter isocaloric protein quantity trial with 0.8 g/kg/day comparator and clearly achieved higher intake, stratified before outcomes by nutrition/frailty and including a factorial resistance-training component; GLP-1-treated adults need their own controlled stratum with measured function.

Readout: Functional primary endpoint such as SPPB, gait or chair rise and prespecified strength at fixed 12–52-week horizon, plus anatomical muscle imaging and DXA/BIA reported separately. Controls: Matched calories, micronutrients/ingredients, counseling, exercise intensity and contact; achieved total protein verified; participant-level ITT with cluster handling and multiplicity; no outcome/adherence-defined beneficiary scope. Supporting: Replicated clinically interpretable functional benefit attributable to protein quantity with baseline-defined interaction and adequate intake separation. Falsifying: Precise functional null despite achieved protein contrast, or package benefit confined to training/micronutrients while protein-only is null.

KNOWLEDGE GAPS

A universal above-RDA target cannot be read from an acute MPS plateau or observational diet association.

The relative contribution of protein quantity, quality, energy correction, vitamin D and exercise needs matched component controls.

Long-term muscle function is not identical to DXA/BIA lean mass or biochemical anabolism.

Achieved intake and baseline frailty/nutrition interactions need independent prospective replication; frailty alone is not a responder definition.

Medication-assisted weight loss protein/training evidence is still directly needed; protocols do not validate all GLP-1 muscle-loss mitigation claims.

Renal state, exposure duration and product ingredients define safety inference; short unchanged creatinine is not all-population safety proof.

REVIEWER NOTES

The registered claim concerns functional benefit of above-RDA quantity, not whether protein is essential. Literal aging-rubric falsification patterns concerning lifespan, reduced growth/sickness or developmental necessity were considered but not imposed on an older-adult nutrition function claim. Already counted context boundaries are not double penalized. The collagen corrigendum is attached without inventing its content; PubMed RCT indexing for PMID 30921603 does not override its original abstract case-control description. Consensus cross-checks are supplemental; source access is bounded and open manual grading is not blind peer review. Coordinating source checks retained Ε/Moderate for the quantified malnourished/pre-frail dose context, with the controlled 0.8-versus 1.3 g/kg feeding null retained. The Park gait result is secondary to a mass-powered trial; PROMISS (PMID 34609621) supplies a functional-primary positive in a different, non-malnourished population, but it is open-label, co-increased energy intake and lost significance per protocol, so independent blinded replication is still needed. Tieland functional benefit cannot certify an unverified achieved total intake, and bundled leucine/vitamin D or resistance training cannot be assigned to protein alone.

Search leads, reviews, protocols and correction notices do not pad the primary count. Downloaded XML does not earn examination credit. Linked notices remain attached; unexamined correction details limit inference. This is a coordinator source/claim consistency assessment, not independent blinded calibration.

Consensus and original-source reconciliation

The examined original 2021 nutrition trial has 208 older adults randomized to carbohydrate, collagen, whey, light training plus whey, or heavy training plus whey for one year. Protein-only arms are null; loading contrasts are positive. This is a retrieval identity error, not missing literature, and no training-only arm proves whey synergy. Original PMID 33564844.

The separate original 65-person nutrition-only trial reports a positive SPPB interaction without lean-mass gain; leg-extension strength is only a trend. This positive functional result prevents an unqualified no-benefit summary. Exact achieved total protein remains unverified at our abstract access depth. Original PMID 22889730.

Original abstract agrees. It is NCT01110369, separate from the 65-person nutrition-only NCT01109628 study. Their endpoint difference does not represent duplicate reporting or contradictory measurements in the same cohort. Original PMID 22770932.

Original abstract agrees with this endpoint hierarchy. Vitamin D, leucine, whey and other nutrients are bundled; the benefit cannot be assigned to protein quantity alone or described as a positive primary functional trial. Original PMID 26170041.

Original selected PMC Methods/Results confirms controlled energy, intake checks and separately analyzed outcomes. This strong null in its baseline-defined group is retained without generalizing to every malnourished or frail older adult. Original PMID 29532075.

Original abstract verifies 80 participants, matched resistance training, actual intake 1.11 versus 0.85 g/kg/day, and preserved appendicular lean mass. Strength and physical function improve over time without between-arm differences; review-level language cannot replace that functional null. Original PMID 25646324.

Original 120-person randomized trial in malnourished prefrail/frail elders directly compares 0.8, 1.2 and 1.5 g/kg/day: highest-dose mass and secondary gait improvement are positive, intermediate-dose outcomes null. The scoped clinical positive is retained while rejecting a universal dose rule. Original PMID 30475969.

Original Methods/Results shows prescribed targets differ from achieved intake, no fat-free-mass protein main or interaction effect, and selected grip/gait interactions. Secondary interactions and positive within-arm changes are not interchangeable with a general protein effect. Original PMID 28166780.

Original abstract identifies the same 380-person RCT plus voluntary open-label extension. It informs product-specific tolerability over six months, not a new independent causal efficacy line or universal renal safety. Original PMID 32162241.

Original OPEN abstract has a null main function result, with body-weight and high-adherence subgroup signals. Adherence after allocation cannot define a preregistered beneficiary group; caregiver-time reanalysis is the same trial. Original PMID 32471657.

Consensus was used to identify literature and cross-check specific claims about design, endpoints, scope and research gaps. Those aspects were checked against original primary abstracts/status records and selected original Methods/Results passages. Consensus output was not treated as original full text. Provider search omissions are not evidence that a study does not exist. Source access and examination receipts are retained. Scite use or monthly unavailability is recorded per case; provider citation counts do not change causal grades.

Research timeline and gaps: Protein Intake and Muscle Function in Older Adults

Selected publication milestones, not an exhaustive history or discovery priority claim.

2006 — 2006 acute EAA/leucine tracer experiments demonstrate composition-sensitive synthesis. Original PMID 16507602.

2012 — 2012 bed rest shows reduced anabolic response, linking inactivity to a physiological boundary. Original PMID 22338078.

2012 — 2012 nutrition-only frailty trial improves SPPB without mass gain. Original PMID 22889730.

2012 — 2012 separate training trial increases lean mass without added strength or SPPB benefit. Original PMID 22770932.

2015 — 2015 PROVIDE retains secondary chair-rise and lean-mass positives with primary functional nulls. Original PMID 26170041.

2015 — 2015 weight-loss formulation preserves lean mass without additional function. Original PMID 25646324.

2017 — 2017 factorial weight-loss study reports modest achieved dose separation and endpoint-specific interactions. Original PMID 28166780.

2018 — 2018 controlled feeding tests above-RDA intake with no functional advantage in its enrolled group. Original PMID 29532075.

2018 — 2018 malnourished frailty dose trial identifies highest-dose mass and gait benefit. Original PMID 30475969.

2020 — 2020 year-long whey trial in sarcopenia reports functional nulls. Original PMID 31734121.

2021 — 2021 CALM separates ineffective protein alone from effective heavy loading. Original PMID 33564844.

2021 — 2021 PRO-Elderly finds no nutrition add-on to training. Original PMID 34358827.

2026 — 2026 small fermented-whey trial supplies a positive multinutrient replication lead. Original PMID 41805014.

2026 — 2026 adequate-intake older-women trial finds training benefits without added leucine. Original PMID 40926079.

Research gaps

A universal above-RDA target cannot be read from an acute MPS plateau or observational diet association.

The relative contribution of protein quantity, quality, energy correction, vitamin D and exercise needs matched component controls.

Long-term muscle function is not identical to DXA/BIA lean mass or biochemical anabolism.

Achieved intake and baseline frailty/nutrition interactions need independent prospective replication; frailty alone is not a responder definition.

Medication-assisted weight loss protein/training evidence is still directly needed; protocols do not validate all GLP-1 muscle-loss mitigation claims.

Renal state, exposure duration and product ingredients define safety inference; short unchanged creatinine is not all-population safety proof.

Boundary experiment

A preregistered multicenter isocaloric protein quantity trial with 0.8 g/kg/day comparator and clearly achieved higher intake, stratified before outcomes by nutrition/frailty and including a factorial resistance-training component; GLP-1-treated adults need their own controlled stratum with measured function.

ADVERSARIAL REVIEW AND APPROVAL

Authoring model: Sol 6.1 (the package records its reviewer as "Codex" and generated_by as "Codex; HSEF v5.3"; recorded, not edited). Adversarial reviewer: Claude Opus 5.5 (Anthropic). Date: 2026-10-14. Round: 2 (new-review inventory, group 1).

Scope of checks. All 56 REFERENCES PMIDs verified against PubMed get_article_metadata for title, first author, journal and year: 56/56 resolve correctly, 0 failures. The four PMIDs cited in prose but correctly kept out of the numbered list were also verified: 40859798 (Published Erratum to the collagen trial), 30281119 (Published Erratum, J Nutr), 27267663 (Phillips, a Letter/Comment on the collagen trial) and 42020128 (the LEAN-PREP Clinical Trial Protocol). No retraction or expression of concern appears in the article-type fields of any of the 60 records checked; the two errata are attached as status_flags on their parent ledger rows and carry no row of their own, as the ledger rule requires. Twelve load-bearing claims were spot-checked against PubMed abstracts: Park's 0.8/1.2/1.5 g/kg dose trial (n=120, 70-85 y, 12 wk, ASM/SMI primary, gait speed secondary, 1.2 g arm null); Tieland's nutrition-only trial (n=65, SPPB interaction P=.02, no mass change, leg-extension strength only a trend at P=.059); Tieland's training trial (n=62, NCT01110369, lean mass gained, strength and SPPB with no interaction); OPTIMen (n=92 men, 6 months, null across LBM, strength, power and physical function, fat mass the one between-group difference); CALM (n=208, 1 y, whey and collagen alone ineffective, heavy training with whey improving qCSA and knee-extensor strength, no training-only arm); PROVIDE (n=380, handgrip and SPPB primaries null between arms, chair-stand and appendicular mass positive as secondaries); Bjorkman's 12-month sarcopenia trial (n=218, no performance, grip or muscle-index benefit, no post-trial mortality difference, 56% mild gastrointestinal effects, home-based exercise advice to all arms); Leenders' 24-week healthy training trial (no supplementation add-on); the 2017 weight-loss factorial (no FFM main or interaction effect, achieved 1.13 vs 0.98 g/kg below the prescribed 1.3 vs 0.8 separation, ages 55-80); Verreijen 2015 (appendicular mass preserved, strength and function improving without between-group difference); and the bed-rest leucine trial (leg lean mass partly preserved, function not). Every spot-checked figure, direction of effect, sample size and endpoint status matched the source. Scoring logic was re-derived: the six universal caps, the metabolism/aging rubric adaptation and its declared non-use of the single-species rule on a directly tested human intervention, the pre-registered primary-subclaim aggregation and the two reported alternatives, the Beta/Gamma/Delta boundary, the decisive-perturbation and discriminating-contrast counts, the role derivation, and the Momentum/Stability/Divergence artifacts. The validate_review.py v5 validator was re-run.

Findings

No scientific finding required a change: the headline letter, the confidence band, all four subclaim levels, the role label, the causal tally and the M/S/D values are unchanged.

Rejected findings (checked, no change)

Lead policy applied — confidence bands and momentum (2026-10-14)

Confidence, two-step test. Step 1: access depth is struck as a determinant. How much of a paper this reviewer could read is neither evidence density nor reproducibility and never justifies a band; the rationale was rewritten accordingly (finding B-3). Step 2: the band was re-derived from what remains. Access depth was not the only thing holding the band down. The surviving determinants are substantive and documented throughout the review: the trials are heterogeneous in formulation (bundled whey, leucine, vitamin D, collagen and multi-ingredient rehabilitation products), in achieved intake (the weight-loss factorial separated 1.13 versus 0.98 g/kg against prescribed targets of 1.3 versus 0.8), in comparator and in endpoint; and the positive and null results do not reproduce across baseline contexts, which is the central finding of the review rather than an artifact of reading. The High text's "reproducibility well-established" is therefore not met. Moderate stands.

Momentum, stricter rule. "Decisive work underway" requires work actually being run that could cross the next threshold; a completed publication or trial never satisfies it, however real the study. Two corrections followed. B-4: PMID 42735207 and PMID 41805014 were cited as momentum evidence and are completed, published randomized trials; they were struck from the artifact and relabelled as evidence in the ledger. B-5, lead-adjudicated: this reviewer escalated rather than decided whether LEAN-PREP, which is genuinely running, could cross the next threshold given that it tests the SC4 medication-assisted boundary while SC3 sets the headline. The lead ruled that it cannot: the next threshold belongs to the registered claim, under the pre-registered primary-subclaim rule a result on SC4 cannot move SC3, and running is necessary but not sufficient - both halves of the definition must hold. The value is therefore Mechanistic only, and the artifact now states that LEAN-PREP is live work on a neighbouring subclaim's boundary so that the information stays in the document.

The second-order Stability consequence, referred and now adjudicated. This reviewer raised but did not decide whether Stability should follow Momentum, declining to extend the B-5 ruling by analogy. The lead adjudicated it on the framework text and made it conditional, since Uncertain requires triggers pointing both directions: change to Stable only if LEAN-PREP is the sole named trigger, and otherwise leave Uncertain and report the others.

LEAN-PREP is the sole named trigger, verified by exhaustive search of the document:

• The two directions in the original Stability text — "precise functional nulls would narrow that application" and "positive controlled component effects could extend it" — are both consequences of a LEAN-PREP result, not a second trigger. "Controlled component effects" refers to LEAN-PREP's own factorial protein and training components.
• Every trial registry identifier in the review (NCT01109628, NCT01110369, NCT01890382, NCT02702037, NTR2323) belongs to a completed, published study already in the ledger. LEAN-PREP is the only prospective programme cited anywhere.
• The KNOWLEDGE GAPS, Research gaps and Boundary experiment sections name work that is needed but not under way, which is not a trigger; the boundary experiment is explicitly a design this review proposes.

Stability is therefore Stable, recorded as finding B-6. The LEAN-PREP sentence and the SC4 scope clarification are kept in full, per the lead, because they remain informative about SC4 even though they are not a trigger on the registered letter.

Residual limitations

• The fused-token defect is only partly repaired, and it is an upstream defect. 480 fused tokens of 14 or more characters remain in the HSEF v5.3 apparatus sections and the per-source evidence cards (for example "Legextensionbetweenarmtrendnotconventionalsignificance", "Oneparentstudycanproducelegitimatesecondaryreports"). The same strings appear in protein-muscle-aging.scorecard.json, and the same defect appears in all five case files of this batch, so it is a defect in the authored text rather than in the markdown builder. The correct repair is a regeneration pass over the batch, not hand-splitting in one file; this reviewer has reported it to the lead rather than attempt it here.
• 52 of 56 ledger rows are recorded at abstract depth, so figures taken from them were verified against publisher abstracts rather than full Methods. Two statements this reviewer could not reach at abstract depth are ones the review attributes to full text it did read, and both are internally consistent with their abstracts: the secondary protein-by-exercise interactions for grip and short gait in the 2017 weight-loss factorial (abstract reports only the fat-free-mass main and interaction effects, both null), and the achieved-intake caveat on the Tieland nutrition-only trial (which the review itself flags as unverified in the abstract).
• The review states that the shipped metabolism/aging rubric does not directly cover a clinical dietary-protein strength/function claim and then applies a declared adaptation. That adaptation is stated, bounded and consistently used, and the framework's cap-precedence rule permits it, but it is a reviewer construction rather than shipped rubric text, so the Γ/Δ boundary for SC3 rests on it.

Approval: Following adversarial review and the corrections listed above, the revised document is approved. - Claude Opus 5.5 (Anthropic), 2026-10-14.

Round 3 (2026-11-02) - independent adversarial review, corrections applied

Adversarial reviewer: Claude Opus 5.5 (Anthropic). Date: 2026-11-02. The full round-3 log and findings file are published with this edition (ADVERSARIAL_REVIEW.protein-muscle-aging.md, adversarial-findings.protein-muscle-aging.json). All seven findings were applied on 2026-11-02:

• P1 (Major): the PROMISS trial (PMID 34609621) is added as reference [57], a ledger row and a discriminating contrast (direction supports; not a decisive perturbation and no positive-unit credit, because it is an open-label, energy-co-increasing advice-plus-food intervention). The AT A GLANCE headline, the final rationale, the SC3 row, the Rank 2 model, the REVIEWER NOTES sentence on functional-primary confirmation and the reader summary were revised. Counts: 57 sources, 62 claims, 24 screened discriminating contrasts; decisive perturbations remain 8 and positive qualifying units remain 1.
• P2 (Minor): the SC2 and SC3 Δ and Ε ladder lines now print their supporting record [22] and its endpoint status.
• P3 (Minor): the Rank 1 model no longer describes CALM as a null protein add-on to training.
• P4 (Minor): the reader summary's confidence wording now matches the evidence-based rationale in the score card; access depth does not set the band.
• P5 (Minor): the Rank 2 model now cites the pooled nine-RCT individual-participant analysis (PMID 37432139; a pooled analysis, so cited in prose and not counted as a primary report) and the OPTIMen/PROMISS contrast.
• P6 (Minor): run-together words in the SC3 row and the remaining HSEF apparatus, inventory and evidence-card text were re-spaced in both this review and the score card (whitespace only; receipt pointers, identifiers and quoted rubric text untouched). This closes the round-2 residual limitation on fused tokens.
• P7 (Editorial): each literal metabolism/aging rubric quotation in the cap audit and the Δ ladder lines is now labelled as shipped rubric text with the applied clinical adaptation stated separately.

Level and confidence: Ε / Moderate, unchanged, as the reviewer recorded. Role of mechanism (reinforcing / stabilizing factor), Momentum, Stability and Divergence unchanged.

REFERENCES

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20. Moro T, Brightwell CR, Deer RR et al. Muscle Protein Anabolic Resistance to Essential Amino Acids Does Not Occur in Healthy Older Adults Before or After Resistance Exercise Training. The Journal of nutrition. 2018. PMID 29796648. DOI: 10.1093/jn/nxy064. Access: abstract_metadata. Study: PMID 29796648.

21. Drummond MJ, Dickinson JM, Fry CS et al. Bed rest impairs skeletal muscle amino acid transporter expression, mTORC1 signaling, and protein synthesis in response to essential amino acids in older adults. American journal of physiology. Endocrinology and metabolism. 2012. PMID 22338078. DOI: 10.1152/ajpendo.00603.2011. Access: abstract_metadata. Study: PMID 22338078.

22. Park Y, Choi JE, Hwang HS. Protein supplementation improves muscle mass and physical performance in undernourished prefrail and frail elderly subjects: a randomized, double-blind, placebo-controlled trial. The American journal of clinical nutrition. 2018. PMID 30475969. DOI: 10.1093/ajcn/nqy214. Access: abstract_metadata. Study: PMID 30475969.

23. Bauer JM, Mikušová L, Verlaan S et al. Safety and tolerability of 6-month supplementation with a vitamin D, calcium and leucine-enriched whey protein medical nutrition drink in sarcopenic older adults. Aging clinical and experimental research. 2020. PMID 32162241. DOI: 10.1007/s40520-020-01519-x. Access: abstract_metadata. Study: PROVIDE_NTR2323.

24. Jacob KJ, Hajj-Boutros G, Sonjak V et al. Resistance training, but not leucine, increased basal muscle protein synthesis and reversed frailty in older women consuming optimized protein intake. GeroScience. 2026. PMID 40926079. DOI: 10.1007/s11357-025-01877-2. Access: abstract_metadata. Study: PMID 40926079.

25. Wimo A, Cederholm T, Irving GF et al. Impact of an exercise and nutrition program on caregiver time with residents in institutional care-A secondary analysis. Alzheimer's & dementia : the journal of the Alzheimer's Association. 2026. PMID 41690799. DOI: 10.1002/alz.71198. Access: abstract_metadata. Study: OPEN_NCT02702037.

26. Niccoli S, Kolobov A, Bon T et al. Whey Protein Supplementation Improves Rehabilitation Outcomes in Hospitalized Geriatric Patients: A Double Blinded, Randomized Controlled Trial. Journal of nutrition in gerontology and geriatrics. 2017. PMID 29252150. DOI: 10.1080/21551197.2017.1391732. Access: abstract_metadata. Study: PMID 29252150.

27. Amini N, Dupont J, Lapauw L et al. A multicomponent intervention consisting of exercise, proteins and omega-3 supplementation to improve sarcopenia in community-dwelling older adults: Lessons learned from a 5-armed randomized controlled feasibility trial. The Journal of frailty & aging. 2026. PMID 41632571. DOI: 10.1016/j.tjfa.2025.100129. Access: abstract_metadata. Study: PMID 41632571.

28. Björkman MP, Suominen MH, Kautiainen H et al. Effect of Protein Supplementation on Physical Performance in Older People With Sarcopenia-A Randomized Controlled Trial. Journal of the American Medical Directors Association. 2020. PMID 31734121. DOI: 10.1016/j.jamda.2019.09.006. Access: abstract_metadata. Study: PMID 31734121.

29. Kang L, Gao Y, Liu X et al. Effects of whey protein nutritional supplement on muscle function among community-dwelling frail older people: A multicenter study in China. Archives of gerontology and geriatrics. 2019. PMID 30921603. DOI: 10.1016/j.archger.2019.03.012. Access: abstract_metadata. Study: PMID 30921603.

30. Lim HS, Jung DH, Kim HY et al. Fermented Whey Protein Supplement Slows the Progression of Frailty and Sarcopenia Among Older Korean Adults: A Randomized Blinded Trial. Journal of medicinal food. 2026. PMID 41805014. DOI: 10.1177/1096620X261430172. Access: abstract_metadata. Study: PMID 41805014.

31. Buondonno I, Sassi F, Carignano G et al. From mitochondria to healthy aging: The role of branched-chain amino acids treatment: MATeR a randomized study. Clinical nutrition (Edinburgh, Scotland). 2020. PMID 31672329. DOI: 10.1016/j.clnu.2019.10.013. Access: abstract_metadata. Study: PMID 31672329.

32. Aas SN, Seynnes O, Benestad HB et al. Strength training and protein supplementation improve muscle mass, strength, and function in mobility-limited older adults: a randomized controlled trial. Aging clinical and experimental research. 2020. PMID 31183750. DOI: 10.1007/s40520-019-01234-2. Access: abstract_metadata. Study: PMID 31183750.

33. Grönstedt H, Vikström S, Cederholm T et al. Effect of Sit-to-Stand Exercises Combined With Protein-Rich Oral Supplementation in Older Persons: The Older Person's Exercise and Nutrition Study. Journal of the American Medical Directors Association. 2020. PMID 32471657. DOI: 10.1016/j.jamda.2020.03.030. Access: abstract_metadata. Study: OPEN_NCT02702037.

34. Ioannidou P, Dóró Z, Schalla J et al. Analysis of combinatory effects of free weight resistance training and a high-protein diet on body composition and strength capacity in postmenopausal women - A 12-week randomized controlled trial. The journal of nutrition, health & aging. 2024. PMID 39232439. DOI: 10.1016/j.jnha.2024.100349. Access: abstract_metadata. Study: PMID 39232439.

35. Loman BR, Luo M, Baggs GE et al. Specialized High-Protein Oral Nutrition Supplement Improves Home Nutrient Intake of Malnourished Older Adults Without Decreasing Usual Food Intake. JPEN. Journal of parenteral and enteral nutrition. 2019. PMID 30565718. DOI: 10.1002/jpen.1467. Access: abstract_metadata. Study: PMID 30565718.

36. Tessier AJ, Lévy-Ndejuru J, Moyen A et al. A 16-week randomized controlled trial of a fish oil and whey protein-derived supplement to improve physical performance in older adults losing autonomy-A pilot study. PloS one. 2021. PMID 34424934. DOI: 10.1371/journal.pone.0256386. Access: abstract_metadata. Study: PMID 34424934.

37. Chanet A, Verlaan S, Salles J et al. Supplementing Breakfast with a Vitamin D and Leucine-Enriched Whey Protein Medical Nutrition Drink Enhances Postprandial Muscle Protein Synthesis and Muscle Mass in Healthy Older Men. The Journal of nutrition. 2017. PMID 28835387. DOI: 10.3945/jn.117.252510. Access: abstract_metadata. Study: PMID 28835387.

38. Moore DR, Churchward-Venne TA, Witard O et al. Protein ingestion to stimulate myofibrillar protein synthesis requires greater relative protein intakes in healthy older versus younger men. The journals of gerontology. Series A, Biological sciences and medical sciences. 2015. PMID 25056502. DOI: 10.1093/gerona/glu103. Access: abstract_metadata. Study: Pooled_original_MPS_data_parent_overlap_unresolved.

39. Mao D, Chen F, Wang R et al. Protein Requirements of Elderly Chinese Adults Are Higher than Current Recommendations. The Journal of nutrition. 2020. PMID 32140711. DOI: 10.1093/jn/nxaa031. Access: abstract_metadata. Study: PMID 32140711.

40. Muscariello E, Nasti G, Siervo M et al. Dietary protein intake in sarcopenic obese older women. Clinical interventions in aging. 2016. PMID 26917955. DOI: 10.2147/CIA.S96017. Access: abstract_metadata. Study: PMID 26917955.

41. Filion ME, Barbat-Artigas S, Dupontgand S et al. Relationship between protein intake and dynapenia in postmenopausal women. The journal of nutrition, health & aging. 2012. PMID 22836702. DOI: 10.1007/s12603-012-0054-8. Access: abstract_metadata. Study: PMID 22836702.

42. Leenders M, Verdijk LB, Van der Hoeven L et al. Protein supplementation during resistance-type exercise training in the elderly. Medicine and science in sports and exercise. 2013. PMID 22968306. DOI: 10.1249/MSS.0b013e318272fcdb. Access: abstract_metadata. Study: PMID 22968306.

43. Yamada M, Kimura Y, Ishiyama D et al. Synergistic effect of bodyweight resistance exercise and protein supplementation on skeletal muscle in sarcopenic or dynapenic older adults. Geriatrics & gerontology international. 2019. PMID 30864254. DOI: 10.1111/ggi.13643. Access: abstract_metadata. Study: PMID 30864254.

44. Chevalier S, Goulet ED, Burgos SA et al. Protein anabolic responses to a fed steady state in healthy aging. The journals of gerontology. Series A, Biological sciences and medical sciences. 2011. PMID 21436253. DOI: 10.1093/gerona/glr036. Access: abstract_metadata. Study: PMID 21436253.

45. Gregorio L, Brindisi J, Kleppinger A et al. Adequate dietary protein is associated with better physical performance among post-menopausal women 60-90 years. The journal of nutrition, health & aging. 2014. PMID 24522467. DOI: 10.1007/s12603-013-0391-2. Access: abstract_metadata. Study: PMID 24522467.

46. Korzepa M, Quinlan JI, Marshall RN et al. Resistance training increases myofibrillar protein synthesis in middle-to-older aged adults consuming a typical diet with no influence of protein source: a randomized controlled trial. The American journal of clinical nutrition. 2025. PMID 40288581. DOI: 10.1016/j.ajcnut.2025.04.019. Access: abstract_metadata. Study: PMID 40288581.

47. Neumann M, Friedmann J, Roy MA et al. Provision of high-protein supplement for patients recovering from hip fracture. Nutrition (Burbank, Los Angeles County, Calif.). 2004. PMID 15105027. DOI: 10.1016/j.nut.2004.01.004. Access: abstract_metadata. Study: PMID 15105027.

48. Gray-Donald K, St-Arnaud-McKenzie D, Gaudreau P et al. Protein intake protects against weight loss in healthy community-dwelling older adults. The Journal of nutrition. 2014. PMID 24357473. DOI: 10.3945/jn.113.184705. Access: abstract_metadata. Study: PMID 24357473.

49. Arentson-Lantz EJ, Fiebig KN, Anderson-Catania KJ et al. Countering disuse atrophy in older adults with low-volume leucine supplementation. Journal of applied physiology (Bethesda, Md. : 1985). 2020. PMID 32191600. DOI: 10.1152/japplphysiol.00847.2019. Access: abstract_metadata. Study: PMID 32191600.

50. Drotningsvik A, Oterhals Å, Flesland O et al. Fish protein supplementation in older nursing home residents: a randomised, double-blind, pilot study. Pilot and feasibility studies. 2019. PMID 30858985. DOI: 10.1186/s40814-019-0421-x. Access: abstract_metadata. Study: PMID 30858985.

51. Neelemaat F, Bosmans JE, Thijs A et al. Post-discharge nutritional support in malnourished elderly individuals improves functional limitations. Journal of the American Medical Directors Association. 2011. PMID 21527171. DOI: 10.1016/j.jamda.2010.12.005. Access: abstract_metadata. Study: PMID 21527171.

52. Nakagawa N, Koyama S, Maruyama K et al. Effects of Nutritional Support with a Leucine-Enriched Essential Amino Acid Supplement on Body Composition, Muscle Strength, and Physical Function in Stroke Patients Undergoing Rehabilitation. Nutrients. 2024. PMID 39770886. DOI: 10.3390/nu16244264. Access: abstract_metadata. Study: PMID 39770886.

53. Bhasin S, Apovian CM, Travison TG et al. Effect of Protein Intake on Lean Body Mass in Functionally Limited Older Men: A Randomized Clinical Trial. JAMA internal medicine. 2018. PMID 29532075. DOI: 10.1001/jamainternmed.2018.0008. Access: full_text_partial. Study: PMID 29532075.

54. Tieland M, van de Rest O, Dirks ML et al. Protein supplementation improves physical performance in frail elderly people: a randomized, double-blind, placebo-controlled trial. Journal of the American Medical Directors Association. 2012. PMID 22889730. DOI: 10.1016/j.jamda.2012.07.005. Access: abstract_metadata. Study: Tieland_nutritiononly_NCT01109628.

55. Verreijen AM, Verlaan S, Engberink MF et al. A high whey protein-, leucine-, and vitamin D-enriched supplement preserves muscle mass during intentional weight loss in obese older adults: a double-blind randomized controlled trial. The American journal of clinical nutrition. 2015. PMID 25646324. DOI: 10.3945/ajcn.114.090290. Access: abstract_metadata. Study: PMID 25646324.

56. Tieland M, Dirks ML, van der Zwaluw N et al. Protein supplementation increases muscle mass gain during prolonged resistance-type exercise training in frail elderly people: a randomized, double-blind, placebo-controlled trial. Journal of the American Medical Directors Association. 2012. PMID 22770932. DOI: 10.1016/j.jamda.2012.05.020. Access: abstract_metadata. Study: Tieland_training_NCT01110369.

57. Reinders I, Visser M, Jyväkorpi SK et al. The cost effectiveness of personalized dietary advice to increase protein intake in older adults with lower habitual protein intake: a randomized controlled trial. European journal of nutrition. 2021. PMID 34609621. DOI: 10.1007/s00394-021-02675-0. Access: full_text_partial. Study: PMID 34609621.

Source-specific evidence cards

[1] The effect of daily protein supplementation, with or without resistance training for 1 year, on muscle size, strength, and function in healthy older adults: A randomized controlled trial.

Shows: 208-adult one-year randomized study finds whey/collagen alone ineffective while heavy training improves quadriceps and strength

Does not show: No training-only arm isolates protein add-on; baseline adequate-intake healthy adults not all frail contexts

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[2] Supplement-based nutritional strategies to tackle frailty: A multifactorial, double-blind, randomized placebo-controlled trial.

Shows: 200-person pre/frail trial finds whey soy leucine or creatine do not enhance training adaptations

Does not show: Shared training stimulus; baseline intake and adherence matter; no denial of exercise effect

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[3] Effects of a vitamin D and leucine-enriched whey protein nutritional supplement on measures of sarcopenia in older adults, the PROVIDE study: a randomized, double-blind, placebo-controlled trial.

Shows: PROVIDE 380 has null between-arm handgrip/SPPB primary outcomes but positive secondary chair-rise and DXA lean mass

Does not show: Whey/leucine/vitamin D bundled; secondary multiplicity; lean tissue not strength; no isolated total protein claim

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[4] Obesity and Metabolic Disease Impair the Anabolic Response to Protein Supplementation and Resistance Exercise: A Retrospective Analysis of a Randomized Clinical Trial with Implications for Aging, Sarcopenic Obesity, and Weight Management.

Shows: Retrospective 32-man mixed-supplement subgroup analysis links baseline obesity with weaker response and selected benefits

Does not show: Post hoc responder/subgroup analysis multi-ingredients and active collagen comparator prevent pure protein attribution

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[5] Improving rehabilitation in sarcopenia: a randomized-controlled trial utilizing a muscle-targeted food for special medical purposes.

Shows: 140 sarcopenic rehabilitation patients randomized to enriched whey or isocaloric formula show improved gait and function

Does not show: Variable 4–8-week discharge horizon multi-ingredients; modified ITT; short clinical scope not ordinary healthy adult supplementation

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. Selected body sections: 1:Methods:paragraph1, 1:Methods:paragraph2, 1:Methods:paragraph5, 1:Methods:paragraph13, 1:Methods:paragraph33, 1:Methods:paragraph37, 2:Results:paragraph59, 2:Results:paragraph70, 2:Results:paragraph84. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[6] Effect of multicomponent intervention on malnutrition in older adults: A multicenter randomized clinical trial.

Shows: 99-person nursing home ONS add-on trial finds no between-arm body composition or functional differences

Does not show: Within-group improvements are not randomized treatment effects; energy/fat/protein bundled

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[7] Effects of adequate dietary protein with whey protein, leucine, and vitamin D supplementation on sarcopenia in older adults: An open-label, parallel-group study.

Shows: Open label supplement versus diet counseling has similar mass/grip outcomes and selected gait improvement

Does not show: Both groups target 1.2–1.5 g/kg; not RDA comparator; unblinded multi-ingredient delivery

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[8] De-Training Effects Following Leucine-Enriched Whey Protein Supplementation and Resistance Training in Older Adults with Sarcopenia: A Randomized Controlled Trial with 24 Weeks of Follow-Up.

Shows: Sarcopenia training/supplement study finds no end-intervention arm difference but selected de-training maintenance

Does not show: All groups instructed ≥1.2 g/kg; later subgroup/horizon; not an 0.8-versus-high protein comparison

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[9] A high whey protein, vitamin D and E supplement preserves muscle mass, strength, and quality of life in sarcopenic older adults: A double-blind randomized controlled trial.

Shows: 60-person six-month enriched whey trial reports better BIA mass, grip and quality of life than isocaloric control

Does not show: Vitamin D/E co-interventions and BIA surrogate; small sample; no isolated protein mechanism

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[10] Effects of nutrition supplementation and physical exercise on muscle mass, muscle strength and fat mass among sarcopenic elderly: a randomized controlled trial.

Shows: 241-person sarcopenia factorial trial reports nutrition and exercise improvements in mass/grip

Does not show: Whey/fish oil/vitamin D mix; per-protocol analysis; effects need ITT and component separation

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[11] Effect of high plant protein/peptide nutrition supplementation on knee osteoarthritis in older adults with sarcopenia: A randomized, double-blind, placebo-controlled trial.

Shows: Protein/peptide trial reports SPPB, grip, mass gains in sarcopenic knee OA

Does not show: Ages 50–70 include outside ≥60; disease-specific proprietary mix; no separate older stratum or verified dose contrast

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[12] Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men: a randomised controlled trial.

Shows: 53 completer men collagen plus matched training show greater DXA FFM and isokinetic strength change

Does not show: Silica comparator not energy/protein matched; correction notice 2025 attached; no evidence every protein adds benefit

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. Selected body sections: 0:Methods:paragraph11, 0:Methods:paragraph14, 0:Methods:paragraph16, 0:Methods:paragraph17, 0:Methods:paragraph24, 1:Results:paragraph0, 1:Results:paragraph1, 1:Results:paragraph9, 1:Results:paragraph13, 1:Results:paragraph16. No complete-paper or supplement audit claimed. ErratumIn: PMID 40859798. Subclaims: SC2, SC3, SC4.

[13] Whey protein, amino acids, and vitamin D supplementation with physical activity increases fat-free mass and strength, functionality, and quality of life and decreases inflammation in sarcopenic elderly.

Shows: 130 sarcopenic older adults enriched whey/EAA/vit D plus matched activity improve mass/grip/ADL versus placebo

Does not show: Multicomponent nutritional intervention and short 12-week horizon; cannot isolate protein quantity or vitamin component

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[14] Effect of a high protein diet and/or resistance exercise on the preservation of fat free mass during weight loss in overweight and obese older adults: a randomized controlled trial.

Shows: Weight-loss factorial study finds no protein main mass effect but selected grip/gait protein-training interactions

Does not show: Actual intake contrast 1.13 vs 0.98 adjusted g/kg below prescribed separation; ages ≥55; secondary interaction multiplicity

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. Selected body sections: 1:Methods:paragraph0, 1:Methods:paragraph1, 1:Methods:paragraph2, 1:Methods:paragraph5, 1:Methods:paragraph7, 2:Results:paragraph4, 2:Results:paragraph8, 2:Results:paragraph15. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[15] Effects of combined nutritional supplementation and exercise on proxy measures of muscle mass, strength, and function in older adults with sarcopenia: a 12-week multicentre RCT.

Shows: Combined HMB/protein/vit D/exercise trial improves BIA proxies, grip and function

Does not show: No factorial component control; cannot assign exercise-package benefit to protein; BIA not direct muscle

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[16] Effects of resistance exercise and fortified milk on skeletal muscle mass, muscle size, and functional performance in middle-aged and older men: an 18-mo randomized controlled trial.

Shows: 18-month factorial fortified milk study has exercise benefits but no milk add-on mass/strength/function

Does not show: Ages 50–79 mixed scope; exceeds registered 52-week horizon; protein/micronutrient/energy mixture

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[17] Resistance versus concurrent training with three assigned protein targets in middle-aged and older women: a randomized 2 × 3 factorial trial.

Shows: 2026 exercise factorial trial assigned 0.8/1.6/2.2 targets finds no protein effect on BIA or key functional outcomes

Does not show: Ages 40–77; complete cases 83/108 and assigned targets not achieved intake proof; null not dose equivalence

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[18] Higher Muscle Protein Synthesis Rates Following Ingestion of an Omnivorous Meal Compared with an Isocaloric and Isonitrogenous Vegan Meal in Healthy, Older Adults.

Shows: 16 older adults tracer crossover finds greater acute MPS after matched omnivorous than vegan meal

Does not show: Whole food matrix single meal; no chronic strength/function; not evidence plant protein cannot work

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC4.

[19] A high proportion of leucine is required for optimal stimulation of the rate of muscle protein synthesis by essential amino acids in the elderly.

Shows: Leucine-rich EAA mixture stimulates elderly acute MPS where lower leucine mixture did not

Does not show: Short tracer rate not muscle accretion/function; groups small; specific composition and healthy context

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC4.

[20] Muscle Protein Anabolic Resistance to Essential Amino Acids Does Not Occur in Healthy Older Adults Before or After Resistance Exercise Training.

Shows: Healthy older longitudinal training study finds preserved EAA MPS response and higher basal MPS with training

Does not show: No randomized high daily protein contrast; exercise benefit not supplementation effect; 2018 erratum attached

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. ErratumIn: PMID 30281119. Subclaims: SC1, SC2, SC3, SC4.

[21] Bed rest impairs skeletal muscle amino acid transporter expression, mTORC1 signaling, and protein synthesis in response to essential amino acids in older adults.

Shows: Seven-day bed rest suppresses EAA-stimulated MPS/mTOR response and reduces leg lean mass

Does not show: Six subjects no longer-term protein functional benefit; disuse model not universal aging resistance

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC2, SC4.

[22] Protein supplementation improves muscle mass and physical performance in undernourished prefrail and frail elderly subjects: a randomized, double-blind, placebo-controlled trial.

Shows: 120 malnourished pre-frail or frail elders randomized 0.8/1.2/1.5 g/kg for 12 weeks show 1.5-arm mass/gait improvement

Does not show: Primary mass not gait; modest secondary effect; 1.2-arm null; findings restricted to malnutrition/frailty

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[23] Safety and tolerability of 6-month supplementation with a vitamin D, calcium and leucine-enriched whey protein medical nutrition drink in sarcopenic older adults.

Shows: PROVIDE follow-up reports tolerability and no observed renal decline with enriched whey drink

Does not show: Same parent 380 RCT plus voluntary open-label extension; no evidence universal renal safety or new independent efficacy

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC4.

[24] Resistance training, but not leucine, increased basal muscle protein synthesis and reversed frailty in older women consuming optimized protein intake.

Shows: 19 pre/frail women with 1.2 g/kg and training have no added leucine MPS/strength/frailty benefit

Does not show: Small study; training plus adequate diet benefits do not quantify 0.8 comparison

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC2, SC3, SC4.

[25] Impact of an exercise and nutrition program on caregiver time with residents in institutional care-A secondary analysis.

Shows: OPEN secondary analysis finds less caregiver time in dementia but not somatic units with combined program

Does not show: Same OPEN cohort as 32471657; cluster/design and resource endpoint; not isolated protein strength effect

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC3, SC4.

[26] Whey Protein Supplementation Improves Rehabilitation Outcomes in Hospitalized Geriatric Patients: A Double Blinded, Randomized Controlled Trial.

Shows: 47 hospitalized elders randomized whey report better grip and knee extensor recovery

Does not show: Hospital duration not fixed 8–52 weeks; rehab context baseline under feeding and achieved above RDA not reported abstract

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC3, SC4.

[27] A multicomponent intervention consisting of exercise, proteins and omega-3 supplementation to improve sarcopenia in community-dwelling older adults: Lessons learned from a 5-armed randomized controlled feasibility trial.

Shows: 58-person ENHANce five arm feasibility trial supplies exploratory functional signals and adherence problems

Does not show: Small arms 9–13 participants and low recruitment; not powered clinical component proof

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[28] Effect of Protein Supplementation on Physical Performance in Older People With Sarcopenia-A Randomized Controlled Trial.

Shows: 218 older sarcopenic adults 12-month whey trial finds no functional, grip or mass benefit or post-trial survival difference

Does not show: Home-exercise advice and gastrointestinal burden; baseline context not all underfed frailty

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[29] Effects of whey protein nutritional supplement on muscle function among community-dwelling frail older people: A multicenter study in China.

Shows: Chinese 115-person frailty study reports between-group whey/training functional differences

Does not show: PubMed-indexed RCT but original abstract describes case-control; do not assume randomization; self-selection/confounding

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[30] Fermented Whey Protein Supplement Slows the Progression of Frailty and Sarcopenia Among Older Korean Adults: A Randomized Blinded Trial.

Shows: 45 older Korean adults 10-week fermented whey trial reports eSPPB between-arm improvement

Does not show: Nutrition profile vitamin D/calcium/magnesium changes with protein; small sample; no isolated above RDA proof

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[31] From mitochondria to healthy aging: The role of branched-chain amino acids treatment: MATeR a randomized study.

Shows: 155 malnourished elders open-label BCAA-versus advice study reports energetic and selected clinical improvements

Does not show: Unblinded dietary/advice contrast mixed nutrient correction; peripheral ATP association not muscle mediation

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC3, SC4.

[32] Strength training and protein supplementation improve muscle mass, strength, and function in mobility-limited older adults: a randomized controlled trial.

Shows: 22 mobility limited very old adults randomized combined training/protein increase muscle size, strength, function

Does not show: No training-only/nutrition-only arm isolates protein; muscle-size and strength changes not correlated

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[33] Effect of Sit-to-Stand Exercises Combined With Protein-Rich Oral Supplementation in Older Persons: The Older Person's Exercise and Nutrition Study.

Shows: OPEN cluster combined nutrition/exercise trial has null main physical function but higher weight and adherent subgroup signals

Does not show: Post-randomization adherence cannot define causal beneficiary; 600 kcal co-intervention; no factorial protein contrast

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[34] Analysis of combinatory effects of free weight resistance training and a high-protein diet on body composition and strength capacity in postmenopausal women - A 12-week randomized controlled trial.

Shows: Postmenopause factorial trial finds RT gains without clear high protein additive effect

Does not show: Mean age 58.2 outside exact ≥60 average; body weight vs FFM target; within-arm gains not between-arm effect

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[35] Specialized High-Protein Oral Nutrition Supplement Improves Home Nutrient Intake of Malnourished Older Adults Without Decreasing Usual Food Intake.

Shows: NOURISH subset recalls show high protein ONS raises nutrient intake without food displacement

Does not show: 30-patient subset no direct strength/function outcome; multiple micronutrients/energy and parent trial overlap

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC4.

[36] A 16-week randomized controlled trial of a fish oil and whey protein-derived supplement to improve physical performance in older adults losing autonomy-A pilot study.

Shows: Fish oil/whey rehabilitation pilot achieves higher protein exposure but poor recruitment and completion

Does not show: 20 randomized 10 complete; stopped non-feasible; no credible efficacy inference

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[37] Supplementing Breakfast with a Vitamin D and Leucine-Enriched Whey Protein Medical Nutrition Drink Enhances Postprandial Muscle Protein Synthesis and Muscle Mass in Healthy Older Men.

Shows: 24 older men breakfast enriched whey 6 weeks raises MPS and appendicular lean mass

Does not show: Vitamin D/leucine/energy versus noncaloric control; no function test; below main 8-week horizon

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC2, SC4.

[38] Protein ingestion to stimulate myofibrillar protein synthesis requires greater relative protein intakes in healthy older versus younger men.

Shows: Pooled original tracer data show older men require higher relative protein dose for acute MPS plateau

Does not show: Retrospective pooled reports not independent new trial; confidence interval wide; no chronic functional dose recommendation

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC4.

[39] Protein Requirements of Elderly Chinese Adults Are Higher than Current Recommendations.

Shows: 14 older Chinese adults graded intake oxidation model estimates protein requirement above local recommendation

Does not show: IAAO surrogate requirement not strength/function; local RNI differs from 0.8 g adult reference

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC4.

[40] Dietary protein intake in sarcopenic obese older women.

Shows: Obese older women hypocaloric 1.2 vs 0.8 prescribed protein study reports preserved estimated muscle mass

Does not show: No clear randomization; BIA/equation mass and within-arm comparison; no functional measure

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC4.

[41] Relationship between protein intake and dynapenia in postmenopausal women.

Shows: Postmenopausal protein intake correlates with relative strength/dynapenia despite RDA-level intake

Does not show: Crosssectional mixed 50–75 age; strength/BW and protein/BW share denominator; no causality

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC3, SC4.

[42] Protein supplementation during resistance-type exercise training in the elderly.

Shows: 60 healthy elders 24-week RT study finds no 15 g protein add-on strength, mass, function effect

Does not show: Moderate supplement dose and baseline adequacy; training benefit retained; not proof all supplements fail

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[43] Synergistic effect of bodyweight resistance exercise and protein supplementation on skeletal muscle in sarcopenic or dynapenic older adults.

Shows: 112 older adults four-arm protein/vit D/exercise study reports combined torque/muscle quality advantage

Does not show: Vitamin D co-intervention; mass benefit in sarcopenic not dynapenic normal mass; endpoint-specific interaction

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[44] Protein anabolic responses to a fed steady state in healthy aging.

Shows: Fed-state insulin/amino acid clamp shows preserved muscle anabolism inactive healthy older women

Does not show: Infusion physiology not dietary daily high protein; no chronic functional benefit or general aging scope

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC4.

[45] Adequate dietary protein is associated with better physical performance among post-menopausal women 60-90 years.

Shows: 387 older women above RDA intake group has better SPPB/PPT but not grip after BMI adjustment

Does not show: Crosssectional habitual intake, health confounding; no causal supplement contrast

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC3, SC4.

[46] Resistance training increases myofibrillar protein synthesis in middle-to-older aged adults consuming a typical diet with no influence of protein source: a randomized controlled trial.

Shows: 10-day matched 1 g/kg source trial finds RT increases integrated MPS with no animal/plant difference

Does not show: Mixed age 50–70 short duration; no chronic functional or above RDA amount comparison

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC1, SC2, SC3, SC4.

[47] Provision of high-protein supplement for patients recovering from hip fracture.

Shows: Hip fracture older patients higher protein liquid 28 days improves albumin but not FIM

Does not show: Other nutrients differ; 4-week outside primary horizon; nutritional marker not function

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC3, SC4.

[48] Protein intake protects against weight loss in healthy community-dwelling older adults.

Shows: NuAge case-control follow-up associates higher dietary protein with less subsequent weight loss

Does not show: Food/energy/appetite confounding; weight loss not direct muscle function and no randomized dose

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC4.

[49] Countering disuse atrophy in older adults with low-volume leucine supplementation.

Shows: Older adult 7-day bed rest leucine RCT preserves leg lean mass but not function

Does not show: Amino acid vs alanine not daily whole protein above RDA; short acute disuse outside primary horizon

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[50] Fish protein supplementation in older nursing home residents: a randomised, double-blind, pilot study.

Shows: Nursing home fish protein pilot shows feasibility and mixed inflammatory markers

Does not show: 24-person 6-week trial does not demonstrate functional benefit; retrospective registration

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC3, SC4.

[51] Post-discharge nutritional support in malnourished elderly individuals improves functional limitations.

Shows: 210 malnourished post-discharge elders randomized nutrition program has weight gain and subgroup functional-limit improvement

Does not show: ITT physical performance/grip/FFM null; energy/counseling/micronutrients bundled; exclusion-based positive

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[52] Effects of Nutritional Support with a Leucine-Enriched Essential Amino Acid Supplement on Body Composition, Muscle Strength, and Physical Function in Stroke Patients Undergoing Rehabilitation.

Shows: Stroke-rehab nutrition RCT has BMI/bone benefits but no strength/motor between-arm difference or renal decline

Does not show: Mixed age and EAA formula; no quantified above RDA protein contrast; dose/horizon context

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[53] Effect of Protein Intake on Lean Body Mass in Functionally Limited Older Men: A Randomized Clinical Trial.

Shows: OPTIMen 92 controlled 0.8 vs 1.3 g/kg six-month trial has null mass, strength, power and physical function

Does not show: Men only medically stable selected function limitations; limited precision for small benefit and no exercise stimulation

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. Selected body sections: PMC5885156 Methods:Participants/Interventions/Exercise/Outcomes; web lines331-367, PMC5885156 Results:Compliance/LeanBodyMass/PhysicalFunction; web lines459-498. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[54] Protein supplementation improves physical performance in frail elderly people: a randomized, double-blind, placebo-controlled trial.

Shows: Frail 65-person 24-week protein only trial reports SPPB improvement without muscle mass increase

Does not show: Leg extension between-arm trend not conventional significance; actual total dose not verified original abstract; not universal benefit

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[55] A high whey protein-, leucine-, and vitamin D-enriched supplement preserves muscle mass during intentional weight loss in obese older adults: a double-blind randomized controlled trial.

Shows: Obese older adult weight loss RCT with matched RT shows enriched protein preserves appendicular lean mass but not strength/function

Does not show: Whey/leucine/vit D mixture; actual 1.11 vs 0.85 g/kg; lean mass benefit not functional efficacy

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[56] Protein supplementation increases muscle mass gain during prolonged resistance-type exercise training in frail elderly people: a randomized, double-blind, placebo-controlled trial.

Shows: 62 frail elders with matched 24-week training gain more DXA lean mass on protein but no additional strength/SPPB benefit

Does not show: Separate training trial from 65-person nutrition-only Tieland; total protein intake not quantified in original abstract; mass gain not function

Access/status: Bounded original primary abstract Results/Findings/conclusion passages and linked-status metadata examined; no complete-abstract audit asserted. No complete-paper or supplement audit claimed. none_found. Subclaims: SC2, SC3, SC4.

[57] The cost effectiveness of personalized dietary advice to increase protein intake in older adults with lower habitual protein intake: a randomized controlled trial.

Shows: 276 community-dwelling adults aged 65 or over with habitual intake below 1.0 g/kg adjusted body weight/day: six months of dietary advice plus protein-enriched foods targeting at least 1.2 g/kg/day improved the primary 400-m walk time versus no advice (-12.4 s, 95% CI -21.8 to -2.9) and leg-extension strength (+32.6 N, 95% CI 10.6 to 54.5)

Does not show: Open-label; control received no advice; energy intake rose 107 kcal/day; only 37.5% reached the target and the per-protocol walk-time effect was not significant; advice-plus-timing arm -4.9 s with CI crossing zero; secondary outcomes exploratory; non-malnourished population and not an isolated protein-quantity contrast

Access/status: Original PMC full body text (PMC8490609) retrieved through PubMed Central on 2026-11-02 and read: Methods (design, intervention, outcomes, sample size, statistical and sensitivity analyses), Results (compliance, 400-m walk, secondary outcomes, sensitivity analyses) and Discussion limitations; tables, figures and supplements not examined. Main result also stated in the secondary report PMID 37347495 (abstract). Added after round-3 adversarial review. none_found. Subclaims: SC3, SC4.

Documentary record

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• ADVERSARIAL_REVIEW.protein-muscle-aging.md
• CONSENSUS_CROSSCHECK.html
• CONSENSUS_CROSSCHECK.md
• RESEARCH_TIMELINE.html
• RESEARCH_TIMELINE.md
• SHA256.txt
• adversarial-findings.protein-muscle-aging.json
• codex-correction-provenance.json
• consensus-validation.json
• edition-approval-audit.json
• protein-muscle-aging.review.md
• protein-muscle-aging.scorecard.json
• reader-summary.json
• research-timeline.json
• validation-report.json
• validation-round2-2026-10-14.json
• validation.txt
• video-insert.md
• web-page.md

Sources: 57 · load-bearing claims: 62 · verified: 62 · unverified: 0 · contradicted: 0 · schema 5.3