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Place · Level 3 · Condition
蛋白 1.2-1.6 g/kg · 力量训练 + leucine + 维D · 30 岁起每年 1% 损失 · GLP-1 时代特殊警告
synergy · 1
Older people should eat less protein is a mistaken cultural expectation, and it damages two things at once: bone matrix and muscle. Bone density and muscle mass decline together and jointly set fall risk, so they are managed together.
cofactor · 4
Age-related 'anabolic resistance': per-meal leucine threshold rises from ~2 g (young) to ~3 g (old) — requires 30-40 g high-quality protein per meal + resistance training to drive mTORC1 and preserve muscle. 1.2-1.6 g protein / kg / d consensus (PROT-AGE 2013).
Anabolic resistance (Bauer 2013): older muscle's MPS response to a given protein dose is ~50% lower. Antidote = 35-40 g protein per meal + RT, not 'gentle senior diet'. The core nutritional intervention for sarcopenia.
Creatine is the best value on the sarcopenia line: paired with strength training it has a consistent effect on both mass and strength, at pennies a day. Taken without training it does far less — what it supplies is how hard you can train, not a substitute for training.
Vitamin D's effect in sarcopenia shows up mainly in the deficient: correcting to sufficiency improves strength and reduces falls. Topping up someone already sufficient buys no more, which matches the conclusion on the bone line.
antagonism · 1
Compressing the eating window also compresses how many times protein can be distributed — and muscle preservation runs on repeated hits of 25-40 g protein with 2.5 g or more of leucine. The conflict is sharpest in older adults.
depletes · 1
Inflammation and muscle form a loop that turns on its own: inflammation accelerates muscle breakdown, less muscle means less anti-inflammatory capacity, reduced activity adds visceral fat, and inflammation rises again. This is why preserving muscle ranks so high in ageing.
regulates · 8
Sarcopenia = muscle mass ↓ + strength ↓ + performance ↓ (EWGSOP2 2019 triad). Fiatarone 1994 NEJM (N=100, mean 87 yo, 10 wk × 80% 1RM): knee-extension strength +174% vs control +9% — atlas's canonical 'frailty ≠ destiny' proof.
Muscle is the largest postprandial glucose sink (~80%); sarcopenia ↓ disposal → IR + HbA1c ↑. Reverse: T2D neuropathy + chronic inflammation + IGF-1 resistance accelerate sarcopenia. GLP-1 era demands protein + resistance training to avoid double deterioration.
Post-menopausal women lose ~0.5-1% lean mass/year — RT is the only evidence-grade A reversal. PROT-AGE 2013 + LIFTMOR consensus: protein 1.2-1.5 g/kg/day + RT 2-3×/wk.
Eating the same, moving the same, yet heavier with a thicker waist — that part is genuinely endocrine, not willpower. Muscle mass is falling with age at the same time, and the two stack, which is why strength work outranks cardio in this window.
Muscle is not lost at a steady rate: roughly 1-1.5% a year from 50 to 60, accelerating to 2-3% after 70, with strength falling faster than size. In women the curve visibly steepens once oestrogen drops at menopause.
EWGSOP2 + Liu 2009 Cochrane: RT in sarcopenic populations shows SMD 0.84 large effect. RT + protein is the only evidence-based intervention; no drugs are approved.
Men get no cliff but a slope: testosterone drifts down with age and muscle drifts with it. What matters on this line is the continuity of resistance training and protein intake, not any single testosterone reading.
→HMB
HMB is a leucine metabolite, 3 g a day. Its strength is blocking breakdown rather than driving synthesis — which is why it fits acute illness, bed rest and undernutrition in older people, and adds little for an ordinary training population.