Whey Protein for Muscle Gain
Whey protein modestly increases lean mass and strength when paired with resistance training, but the real driver is hitting enough total daily protein rather than anything unique to whey itself.
Why this grade7-layer evidence engine
Five meta-analyses point the same direction. Cermak's 2012 pooled analysis (PMID 23134885, n=680) found protein supplementation added 0.69 kg of fat-free mass and 13.5 kg to leg-press strength, and Morton's 2018 review (PMID 28698222, n=1863) confirmed gains in mass and strength specifically in trained adults. Whey-focused analyses agree (PMID 31041966; PMID 39303495), so the effect is real and consistent, earning a moderate rather than top grade.
The grade is held at moderate because the effect is small and not unique to whey. Morton 2018 (PMID 28698222) showed benefits plateau once total intake reaches about 1.6 g/kg/day, the 2024 older-adult review (PMID 39303495) found no benefit from whey without resistance training, and the 2026 network meta-analysis (PMID 41635649, n=4755) put whey's strength effect at a modest SMD of 0.15, with collagen actually ranking higher. Note that Morton 2018's lead author received dairy-industry honoraria.
Regulators and clinicians mirror this nuance. The FDA treats whey as a generally-recognized-as-safe food ('FDA has no questions'), and EFSA authorizes a general protein-and-muscle claim but not any whey-specific one. The UK NHS is cautious, saying non-elite athletes are 'unlikely to benefit' and should get protein from food first, while Mayo Clinic supports it as one way to 'protect your muscles.' The bottom line: helpful as a convenient protein source, not a muscle-building shortcut.
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.735
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (4 篇 > 0 negative)
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status