Place · Level 3 · Condition
Sarcopenia · The Silent Killer of Aging
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
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Chapter 1
Not just 'old skinny'
Not just 'old skinny'
Sarcopenia = age-related progressive decline in skeletal-muscle mass + strength + function. It is not as simple as "getting old and skinnier" — it is one of the most preventable killers of older-adult health.
EWGSOP2 (Europe) + AWGS 2019 (Asia) diagnostic criteria:
1. Low muscle strength (screening threshold):
Grip strength < 28 kg in men / < 18 kg in women (Asian standard)
2. Low muscle mass (confirmation):
DXA / BIA: men < 7.0 / women < 5.4 kg/m² (Asian)
3. Low function (severe-disease marker):
Gait speed ≤ 0.8 m/s (10 m test) or 5-times sit-to-stand ≥ 11 s
Epidemiology (Cruz-Jentoft 2019 Lancet + Chinese data):
65+ y/o China 14-19% (higher along the coast)70+ y/o jumps to 20-30%80+ y/o ~ 50%Female + advanced age + poor nutrition + sedentariness + chronic disease = stacking risk
Why this is "the first preventable killer":
Falls + fractures: sarcopenia → poor balance → ↑ falls → hip fracture (50% 1-year mortality)Metabolic syndrome: muscle is the body's largest glucose sink → sarcopenia → ↑ IR → T2D / CVDImmune decline: muscle is the amino-acid reservoir → in severe illness / infection, mobilisation fails → ↑ mortalityIndependence: sarcopenia → cannot climb stairs / carry / get out of bed → disability → nursing-homePremature death: muscle mass shows an inverse dose-response with all-cause mortality in older adults (Wang 2020 meta-analysis)
Timeline:
20-30 y/o: peak muscle massFrom age 30: 0.5-1% loss per year (more in the sedentary)50-60 y/o: accelerates to 1-1.5%/year70+ y/o: accelerates to 2-3%/year + faster strength loss (fat infiltration + neuromuscular-junction degeneration)Menopausal women: estrogen drop → acceleration (mentioned in atlas perimenopause L4)Male LOH: gradual T decline + gradual muscle decline (atlas andropause L4)
The "eat lightly, less meat" cultural trap:
The cultural expectation among Chinese seniors of "light eating / less meat / more vegetables"In reality protein intake is severely insufficient — average Chinese senior protein intake in 2020 was ~ 0.7-0.9 g/kg (recommended 1.2-1.6)One of the main reasons for the high sarcopenia prevalence
Atlas connections:
protein L3 + protein/digest + muscle (MPS mechanism)vitamin-d L4 (D and muscle)hmb (β-leucine metabolite + anti-catabolism)creatine (5 g/day effective in older adults)endocrine/HPG + andropause + perimenopause (hormones)glucagon-like peptide-1: A gut hormone released after eating that makes you feel full and helps lower blood sugar. era (weight-loss drugs + muscle-loss warning — below)
EWGSOP2 (Europe) + AWGS 2019 (Asia) diagnostic criteria:
1. Low muscle strength (screening threshold):
Grip strength < 28 kg in men / < 18 kg in women (Asian standard)
2. Low muscle mass (confirmation):
DXA / BIA: men < 7.0 / women < 5.4 kg/m² (Asian)
3. Low function (severe-disease marker):
Gait speed ≤ 0.8 m/s (10 m test) or 5-times sit-to-stand ≥ 11 s
Epidemiology (Cruz-Jentoft 2019 Lancet + Chinese data):
65+ y/o China 14-19% (higher along the coast)70+ y/o jumps to 20-30%80+ y/o ~ 50%Female + advanced age + poor nutrition + sedentariness + chronic disease = stacking risk
Why this is "the first preventable killer":
Falls + fractures: sarcopenia → poor balance → ↑ falls → hip fracture (50% 1-year mortality)Metabolic syndrome: muscle is the body's largest glucose sink → sarcopenia → ↑ IR → T2D / CVDImmune decline: muscle is the amino-acid reservoir → in severe illness / infection, mobilisation fails → ↑ mortalityIndependence: sarcopenia → cannot climb stairs / carry / get out of bed → disability → nursing-homePremature death: muscle mass shows an inverse dose-response with all-cause mortality in older adults (Wang 2020 meta-analysis)
Timeline:
20-30 y/o: peak muscle massFrom age 30: 0.5-1% loss per year (more in the sedentary)50-60 y/o: accelerates to 1-1.5%/year70+ y/o: accelerates to 2-3%/year + faster strength loss (fat infiltration + neuromuscular-junction degeneration)Menopausal women: estrogen drop → acceleration (mentioned in atlas perimenopause L4)Male LOH: gradual T decline + gradual muscle decline (atlas andropause L4)
The "eat lightly, less meat" cultural trap:
The cultural expectation among Chinese seniors of "light eating / less meat / more vegetables"In reality protein intake is severely insufficient — average Chinese senior protein intake in 2020 was ~ 0.7-0.9 g/kg (recommended 1.2-1.6)One of the main reasons for the high sarcopenia prevalence
Atlas connections:
protein L3 + protein/digest + muscle (MPS mechanism)vitamin-d L4 (D and muscle)hmb (β-leucine metabolite + anti-catabolism)creatine (5 g/day effective in older adults)endocrine/HPG + andropause + perimenopause (hormones)glucagon-like peptide-1: A gut hormone released after eating that makes you feel full and helps lower blood sugar. era (weight-loss drugs + muscle-loss warning — below)
连锁 · 肌肉少了会塌什么
为什么说它是老年最该早防的一关? 因为肌肉少了, 后面是一串连锁的塌方:跌倒和骨折: 肌肉撑不住身体, 平衡变差, 一摔就是髋骨折——而髋骨折一年内死亡率高达 50%血糖失控: 肌肉少了, 血糖没处去, 胰岛素抵抗加重, 推向 2 型糖尿病和心血管病扛不住大病: 重病或感染时, 身体要从肌肉这个仓库里调兵, 库存空了, 死亡率就上去失去独立: 爬不动楼、起不了床、提不动菜, 一步步走向失能、走向养老院更早离世: 老年人肌肉越少, 全因死亡率越高, 是清楚的剂量关系 (Wang 2020 meta)
时间线 · 它是怎么一年年掉的
它是怎么一年年掉下去的:20-30 岁: 肌肉量到顶30 岁起: 每年掉 0.5-1% (不锻炼的掉更多)50-60 岁: 加速到 1-1.5%/年70 岁后: 再加速到 2-3%/年, 而且力气掉得比肌肉块头还快 (肌肉里渗进脂肪, 神经和肌肉的接头也在退化)女性绝经后: 雌激素一掉, 流失提速 (atlas perimenopause L4 讲过)男性进入睾酮缓降期 (LOH): 睾酮慢慢降, 肌肉也跟着慢慢降 (atlas andropause L4)
中国老人身上还压着一个文化陷阱: 一辈子被教吃清淡、少吃肉、多吃菜, 结果蛋白严重吃不够——2020 年中国老人平均蛋白摄入只有约 0.7-0.9 g/kg, 而推荐是 1.2-1.6。这是肌少症在国内特别普遍的主因之一。
临床 · 医生怎么确诊
医生怎么确诊 (EWGSOP2 欧洲 + AWGS 2019 亚洲标准, 按亚洲人切点) 大致是三关: 先量握力做筛查, 男 < 28 kg、女 < 18 kg 算偏弱; 再用 DEXA 或 BIA 测肌肉量确诊, 男 < 7.0、女 < 5.4 kg/m²; 走得太慢 (10 米步速 ≤ 0.8 m/s) 或起坐 5 次要 ≥ 11 秒, 说明已经影响到功能。患病率随年龄陡升 (Cruz-Jentoft 2019 Lancet + 中国研究): 65 岁以上中国约 14-19% (沿海更高), 70 岁以上跳到 20-30%, 80 岁以上接近一半。女性、高龄、营养差、久坐、慢病这些因素叠在一起风险最高。顺着地图往下走
想往深处看, 可以顺着 atlas 这些岛走: protein L3 加 protein/digest 加 muscle 看肌肉怎么长出来; vitamin-d L4 看 D 和肌肉; hmb 看那个抗分解的亮氨酸代谢物; creatine 看老年人 5 g/天的证据; endocrine/HPG 加 andropause 加 perimenopause 看激素; 减重药那一块的肌肉损失警告就在本故事下文。Chapter 2
Protein RDA · senior reality
Protein RDA · senior reality
"Protein RDA = 0.8 g/kg" is one of the most-misread numbers in medical nutrition.
What 0.8 g/kg RDA actually means:
It is the minimum to prevent negative nitrogen balance + in a perfectly healthy young adultNot "optimal," not "for older adults," not "during illness recovery"The IOM acknowledged in 2005 that this was the lower bound
Real older-adult requirement (PROT-AGE Study Group 2013, ESPEN 2014):
Healthy 65+ y/o: 1.0-1.2 g/kg/day65+ + chronic / acute disease / nutritional risk: 1.2-1.5 g/kg/day65+ + severe acute / chronic disease: up to 2.0 g/kg/dayCKD stages 4-5 not on dialysis: exception — restrict protein (consult nephrology)
Why older adults need more:
① Blunted muscle-protein-synthesis (MPS) response ("anabolic resistance"):
The same 1 g leucine triggers MPS in the young but may not in older adultsTrigger threshold: older adults need 25-40 g protein + 2.5-3 g leucine per mealThis is the leucine-mechanistic target of rapamycin: The cell's master 'grow / build' switch — turned on by enough protein and resistance training. mechanism in atlas protein/muscle L4
② Reduced absorption + utilisation:
Older-adult gastric acid ↓ → reduced protein digestion efficiencyBowel motility + absorption efficiency declineSplanchnic extraction: more of the absorbed amino acids are taken by gut + liver, less reaching peripheral muscle
③ Higher protein turnover:
Chronic low-grade inflammation (inflammaging) → persistently higher protein demandAccumulated chronic illness → ongoing repair demandAcute illness (pneumonia / fall / surgery) → short-term up to 2 g/kg
Distribution matters too (Mamerow 2014):
Even distribution: 25-40 g at breakfast / lunch / dinner > 80 g concentrated at dinnerEach meal must exceed the MPS trigger + leucine threshold
Leucine content:
1 egg = 0.5 g leucineChicken breast (100 g) = 2.5 gBeef (100 g) = 2.5 gSalmon (100 g) = 1.5 gSoybeans (50 g dry) = 2.0 gWhey protein (25 g) = 2.5-3 g leucine (high concentration, well suited to senior supplementation)Cooked rice (100 g) = 0.2 g (far below the threshold)
Practice:
25-40 g protein per meal (with 2.5+ g leucine) — this is what older adults need, not "less meat"Breakfast protein matters most — most seniors get 5-10 g protein at breakfast (steamed bun, congee, rice porridge), far below the thresholdWhey supplementation (15-25 g per scoop) is the highest-ROI supplementation tool for seniors — combined with food, not as a replacement
High-quality protein sources ranked for older adults:
1. Whey / eggs / fish / lean meat / chicken (high leucine + easy to digest)
2. Dairy (yogurt / milk)
3. Soy / tofu
4. Grain + legume blends: improves amino-acid completeness
What 0.8 g/kg RDA actually means:
It is the minimum to prevent negative nitrogen balance + in a perfectly healthy young adultNot "optimal," not "for older adults," not "during illness recovery"The IOM acknowledged in 2005 that this was the lower bound
Real older-adult requirement (PROT-AGE Study Group 2013, ESPEN 2014):
Healthy 65+ y/o: 1.0-1.2 g/kg/day65+ + chronic / acute disease / nutritional risk: 1.2-1.5 g/kg/day65+ + severe acute / chronic disease: up to 2.0 g/kg/dayCKD stages 4-5 not on dialysis: exception — restrict protein (consult nephrology)
Why older adults need more:
① Blunted muscle-protein-synthesis (MPS) response ("anabolic resistance"):
The same 1 g leucine triggers MPS in the young but may not in older adultsTrigger threshold: older adults need 25-40 g protein + 2.5-3 g leucine per mealThis is the leucine-mechanistic target of rapamycin: The cell's master 'grow / build' switch — turned on by enough protein and resistance training. mechanism in atlas protein/muscle L4
② Reduced absorption + utilisation:
Older-adult gastric acid ↓ → reduced protein digestion efficiencyBowel motility + absorption efficiency declineSplanchnic extraction: more of the absorbed amino acids are taken by gut + liver, less reaching peripheral muscle
③ Higher protein turnover:
Chronic low-grade inflammation (inflammaging) → persistently higher protein demandAccumulated chronic illness → ongoing repair demandAcute illness (pneumonia / fall / surgery) → short-term up to 2 g/kg
Distribution matters too (Mamerow 2014):
Even distribution: 25-40 g at breakfast / lunch / dinner > 80 g concentrated at dinnerEach meal must exceed the MPS trigger + leucine threshold
Leucine content:
1 egg = 0.5 g leucineChicken breast (100 g) = 2.5 gBeef (100 g) = 2.5 gSalmon (100 g) = 1.5 gSoybeans (50 g dry) = 2.0 gWhey protein (25 g) = 2.5-3 g leucine (high concentration, well suited to senior supplementation)Cooked rice (100 g) = 0.2 g (far below the threshold)
Practice:
25-40 g protein per meal (with 2.5+ g leucine) — this is what older adults need, not "less meat"Breakfast protein matters most — most seniors get 5-10 g protein at breakfast (steamed bun, congee, rice porridge), far below the thresholdWhey supplementation (15-25 g per scoop) is the highest-ROI supplementation tool for seniors — combined with food, not as a replacement
High-quality protein sources ranked for older adults:
1. Whey / eggs / fish / lean meat / chicken (high leucine + easy to digest)
2. Dairy (yogurt / milk)
3. Soy / tofu
4. Grain + legume blends: improves amino-acid completeness
这个数到底量的是什么
这个 0.8 g/kg 到底是什么意思? 它是不让身体亏空的最低线: 定这个数时, 科学家问的是一个完全健康的年轻成年人, 至少得吃多少蛋白, 才不至于让身上的蛋白净往外流。注意这三个词——最低、健康、年轻。它从来就不是吃得最好的量, 不是上了年纪该有的量, 更不是生病、康复期的量。制定它的机构 (IOM) 2005 年就明说了: 这是下限, 不是目标。另外两条原因
为什么同样是人, 老了就得多吃? 三条线拧在一起, 第一条 (合成抵抗) 开头那一页讲过了。第二条: 吃进去的, 有一部分根本没送到肌肉。 老人胃酸少了, 蛋白消化得没那么彻底; 肠子蠕动、吸收也慢了; 更麻烦的是, 好不容易吸收进来的氨基酸, 有更大一块被肠子和肝脏半路截下自己用了 (医学上叫内脏截取, splanchnic extraction), 真正分到腿上、胳膊上肌肉的就少了。
第三条: 老人身上的蛋白消耗本来就大。 上了年纪常伴着一种低烧似的慢性炎症 (inflammaging), 身体一直在悄悄拆自己的蛋白; 各种慢病也在不停要料修补; 一旦碰上肺炎、跌倒、手术这种急事, 需求短期就能冲到 2 g/kg。
该吃多少 · 老年共识给的数
人一老, 真实的需求要高出一截 (这是 PROT-AGE 2013、ESPEN 2014 这些老年营养共识给的数):身体还硬朗的 65 岁以上: 每天 1.0-1.2 g/kg/天65 岁以上, 还带着慢病、刚生过急病、或本就有营养风险: 提到 1.2-1.5 g/kg/天重病、慢病重度那阵: 短期可以到 2.0 g/kg一个重要例外: 已经到慢性肾病 (CKD) 4-5 期、还没开始透析的人, 反过来要限蛋白, 这一条必须听肾内科医生的 (为什么肾不好要限蛋白, 本幕下面那一页专门讲)
Protein + kidney myth
"Older adults eating more protein damages the kidneys" is an overgeneralisation.The truth:
Healthy renal function (eGFR > 60): high protein (≤ 2 g/kg/day) does not damage the kidneys (Devries 2018 + Antonio 2016 + multiple meta-analyses)CKD stage 1-3a (eGFR ≥ 45): moderate protein (1.0-1.2 g/kg) more likely benefits muscle than harms the kidneyCKD stage 3b-5 not on dialysis (eGFR < 45): genuinely needs protein restriction (0.6-0.8 g/kg) — strict nephrology guidanceCKD 5 on dialysis: protein requirements rise (1.2-1.5 g/kg) because of dialysis losses
Why the misconception persists:
1980-90s RCTs in CKD patients showed protein restriction slowed progressionMistakenly generalised to healthy older adults"Protein damages kidneys" is not supported by modern nephrology in healthy people
Practice:
Don't know your renal function: at 65+, check eGFR + urine albumin annuallyeGFR > 60: eat 1.2-1.6 g/kg comfortablyeGFR 45-60: moderate (1.0-1.2 g/kg)eGFR < 45: see nephrology, individualise
What can actually damage the kidneys:
Long-term NSAIDs (ibuprofen / naproxen)Long-term uncontrolled diabetesLong-term uncontrolled hypertensionCertain herbal products (containing aristolochic acid) — atlas warningNot protein
devries-2018-protein-kidney
怎么吃 · 分配与饭桌
还有件容易被忽略的事: 不光看吃多少, 还看怎么分。 三餐每顿都吃够 25-40 g, 效果比白天将就、晚上一口气灌 80 g 要好 (Mamerow 2014)——因为每一顿都得单独越过那道点火的门槛, 攒到晚上一次吃再多, 也补不回白天空掉的那两顿。落到饭桌上, 就这么几句:
每顿奔着 25-40 g 蛋白去 (里头有 2.5 g 以上亮氨酸)——这才是老人该有的吃法, 不是少吃肉早餐尤其要盯紧: 多数老人早上一碗粥、一个馒头, 蛋白才 5-10 g, 差得远一勺乳清蛋白 (15-25 g) 是最划算的补法, 但它是给正餐搭把手, 不是拿它顶饭
挑食物 · 亮氨酸在哪儿
说到亮氨酸, 各种食物差得挺远, 心里有个谱就够了:一个鸡蛋大约 0.5 g100 g 鸡胸、100 g 牛肉, 各约 2.5 g100 g 三文鱼约 1.5 g50 g 干大豆约 2.0 g一勺乳清蛋白 (25 g) 能到 2.5-3 g, 浓度高, 特别适合老人补而 100 g 熟米饭只有 0.2 g, 离点火线远得很
蛋白源怎么挑? 大致这么排: 乳清、鸡蛋、鱼、瘦肉、鸡最靠前 (亮氨酸高又好消化); 其次是酸奶、牛奶这类奶制品; 再往后是大豆、豆腐; 谷物和豆子搭着吃, 能把氨基酸补得更齐全。
Chapter 3
Resistance training · 60+ miracle
Resistance training · 60+ miracle
Resistance training is the only first-line intervention for sarcopenia — 10× stronger than any supplement.
Fiatarone 1994 NEJM classic RCT:
N = 100 extremely frail elderly (mean age 87) in nursing homes10 weeks of high-intensity resistance training (legs, 80% 1RM)Results:Strength ↑ 113%Gait speed ↑ 12%Stair-climb power ↑ 28%Several who needed wheelchairs walked independently after training
This RCT shifted the paradigm of geriatric medicine: "still trainable at 80+" is not a slogan.
Mechanism:
Mechanical loading → satellite-cell activation → fiber hypertrophyNeuromuscular-junction rebuilding (neurological decline drives some of the strength loss in older adults)↑ muscle mass + ↓ fat infiltration (myosteatosis)Hormonal: T + GH + IGF-1 briefly ↑
Dose (ACSM 2018 + AHA 2024):
Frequency: 2-3×/week, non-consecutive daysEach major muscle group (legs / back / chest / shoulders / core): 2-3 sets × 8-12 repsIntensity: 60-80% 1RM (safe range for older adults); the "could do 1-2 more reps but not 5" feelingProgression: increase weight / reps every 2-4 weeks
At-home practice (no gym required):
Chair stand: arms crossed at chest + sit-to-stand × 10 reps × 3 setsWall push-up: senior-friendly version, progressiveResistance band: cheap, versatile, senior-friendlyDumbbells (1-5 kg) or water bottlesLeg raises / side leg raises (balance + hip abduction)
Aerobic + strength:
150 min/week moderate aerobic + 2-3×/week strength = the gold combination for senior healthPlain walking / strolling is insufficient to maintain muscleStrength training prevents sarcopenia more effectively than aerobic alone
Nutrient synergy (anabolic window):
Within 2-3 h post-training, ingest 25-40 g protein + leucine → MPS maximisedWhey after training + with a regular meal: a classic senior protein-replenishment strategyVitamin D + Mg + adequate calories form the supporting base
Protein + training combined (Phillips 2017 review):
Protein alone: small strength improvementTraining alone: substantial improvementCombined: greatest effect
Safety + senior specifics:
Fall history + severe OA: collaborate with rehabilitation / geriatricsStable CVD: low-to-moderate intensity safe; high intensity requires assessmentBalance training: tai chi / yoga + strength = gold combination for fall prevention
"Old people can't build muscle" is wrong:
The hypertrophic response still exists in older adults, just slowerMuscle mass gains are possible at 80+ (Fiatarone proved it)The key is to start today, not "from a young age""It is not too late — earlier is better"
Fiatarone 1994 NEJM classic RCT:
N = 100 extremely frail elderly (mean age 87) in nursing homes10 weeks of high-intensity resistance training (legs, 80% 1RM)Results:Strength ↑ 113%Gait speed ↑ 12%Stair-climb power ↑ 28%Several who needed wheelchairs walked independently after training
This RCT shifted the paradigm of geriatric medicine: "still trainable at 80+" is not a slogan.
Mechanism:
Mechanical loading → satellite-cell activation → fiber hypertrophyNeuromuscular-junction rebuilding (neurological decline drives some of the strength loss in older adults)↑ muscle mass + ↓ fat infiltration (myosteatosis)Hormonal: T + GH + IGF-1 briefly ↑
Dose (ACSM 2018 + AHA 2024):
Frequency: 2-3×/week, non-consecutive daysEach major muscle group (legs / back / chest / shoulders / core): 2-3 sets × 8-12 repsIntensity: 60-80% 1RM (safe range for older adults); the "could do 1-2 more reps but not 5" feelingProgression: increase weight / reps every 2-4 weeks
At-home practice (no gym required):
Chair stand: arms crossed at chest + sit-to-stand × 10 reps × 3 setsWall push-up: senior-friendly version, progressiveResistance band: cheap, versatile, senior-friendlyDumbbells (1-5 kg) or water bottlesLeg raises / side leg raises (balance + hip abduction)
Aerobic + strength:
150 min/week moderate aerobic + 2-3×/week strength = the gold combination for senior healthPlain walking / strolling is insufficient to maintain muscleStrength training prevents sarcopenia more effectively than aerobic alone
Nutrient synergy (anabolic window):
Within 2-3 h post-training, ingest 25-40 g protein + leucine → MPS maximisedWhey after training + with a regular meal: a classic senior protein-replenishment strategyVitamin D + Mg + adequate calories form the supporting base
Protein + training combined (Phillips 2017 review):
Protein alone: small strength improvementTraining alone: substantial improvementCombined: greatest effect
Safety + senior specifics:
Fall history + severe OA: collaborate with rehabilitation / geriatricsStable CVD: low-to-moderate intensity safe; high intensity requires assessmentBalance training: tai chi / yoga + strength = gold combination for fall prevention
"Old people can't build muscle" is wrong:
The hypertrophic response still exists in older adults, just slowerMuscle mass gains are possible at 80+ (Fiatarone proved it)The key is to start today, not "from a young age""It is not too late — earlier is better"
证据 · 改写了老年医学的那场试验
这不是口号, 底下压着一个几乎改写了老年医学观念的经典试验。1994 年发在《新英格兰医学杂志》上的那项研究 (Fiatarone 1994 NEJM), 找的是一群平均 87 岁、住在养老院、身体已经很虚弱的老人, 一共 100 人。让他们练了 10 周高强度力量训练, 主要练腿, 重量压到各自最大力气的八成 (80% 1RM)。10 周后: 肌肉力气涨了 113%, 走路速度快了 12%, 爬楼的劲儿多了 28%; 几个原本离不开轮椅的老人, 练完能自己走了。这项研究第一次让整个领域信了: 八十多岁, 照样练得出来, 真不是一句安慰话。
最后戳破一个常见的错觉——老了就练不出来了。 不对。老人的肌肉照样会因为训练而变粗, 只是慢一些; 八十多岁也能长肌肉, Fiatarone 那群老人早证明过了。真正的关键是今天就开始, 而不是得从年轻开始——不是太晚, 而是越早越好。
剂量 · 练多重、练几次
剂量不用背得太死, 大方向是这样 (ACSM 2018、AHA 2024):频率: 每周 2-3 次, 别连着两天练同一块每个大肌群 (腿、背 / 胸、肩 / 腹): 做 2-3 组, 每组 8-12 次强度: 用最大力气的六到八成 (60-80% 1RM), 对老人是安全区间; 找那种还能再做 1-2 次、但绝做不到第 5 次的感觉进阶: 每隔 2-4 周加点重量或次数
没有健身房也完全能练:
从椅子上站起来再坐下: 双手抱在胸前, 一组 10 次, 做 3 组靠墙俯卧撑: 站着推墙的老人版, 慢慢加量弹力带: 便宜、花样多、对老人友好小哑铃 (1-5 kg), 或者装了水的瓶子抬腿、侧抬腿: 顺便练平衡和髋部
配套 · 有氧、练后营养与安全
有一点得说清楚: 光散步不够。 每周 150 分钟中等强度有氧 (快走、慢跑) 配上每周 2-3 次力量, 才是老年健康的黄金搭配; 单纯溜达那点强度, 挡不住肌肉流失——防肌少症这件事上, 力量训练比有氧顶用得多。练完别忘了配营养。练完 2-3 小时里补上 25-40 g 蛋白 (带亮氨酸), 肌肉合成能拉到最满; 老人常用的老套路就是练后一勺乳清 + 一顿正经饭, 底下再垫上够吃的热量、维生素 D 和镁。蛋白和训练得合起来用才行 (Phillips 2017 综述): 只补蛋白不练, 力气长一点点; 只练不补蛋白, 长得明显; 两样一起上, 效果最强。
安全上要留神几种情况: 摔过跤、或者骨关节炎 (OA) 很重的, 最好先跟康复科、老年科医生商量着来; 有心血管病但情况稳定的, 低到中等强度是安全的, 想上高强度得先评估。想更稳妥, 太极、瑜伽这类平衡训练配上力量, 是防跌倒最好的组合。
Chapter 4
GLP-1 era · muscle warning
GLP-1 era · muscle warning
New warnings for the glucagon-like peptide-1: A gut hormone released after eating that makes you feel full and helps lower blood sugar. weight-loss drug (semaglutide / tirzepatide) era:
The problem:
GLP-1 class produces 15-20% weight loss over 12-24 monthsBut 25-40% of that loss is muscle, not just fat (Wilding 2021 STEP-1 and follow-up analyses)Older adults with high GLP-1 exposure → accelerated sarcopenia + ↑ falls / fracture risk
Why GLP-1 reduces muscle:
Appetite suppression → substantial protein-intake dropReduced overall food → insufficient MPS triggeringRapid weight loss itself causes muscle loss (all rapid-weight-loss methods do)Older-adult anabolic resistance worsens the problem
"Muscle-Centric Medicine" (Lyon 2025 ACSM consensus):
GLP-1 + high protein + strength training = mandatory bundleProtein target: 1.6-2.0 g/kg/day while on GLP-1 (toward the upper bound in older adults) — ⚠️ applies only when eGFR ≥ 60 mL/min/1.73m²; CKD stage 3a-5 needs nephrology-led stratification by eGFR (0.6-0.8 g/kg + high-quality protein); see the "protein and renal function" sub-page in this storyStrength training 2-3×/weekDon't just watch the scale — monitor muscle change by DXA / BIA
Same problem with "caloric restriction" weight loss (not only GLP-1):
Any rapid weight loss is accompanied by muscle lossOlder adults are especially vulnerableVLCD (DiRECT 850 kcal/day) should be used cautiously in older adults — high muscle-loss risk
Ideal weight-loss strategy (older / middle-aged with sarcopenia risk):
Slow (0.5-1 kg/month, not 1 kg/week)Protein 1.6-2.0 g/kgStrength training 2-3×/weekDXA every 3-6 months to monitor muscle + fatGLP-1 under supervision, not OTC
Weight loss ≠ fat loss:
"Weight loss" reads the scale (water + muscle + fat mixed)"Fat loss" reads body composition (DXA / BIA / waist)Fat loss + muscle gain + stable weight = healthy goal
Senior supplement toolkit (with evidence):
① Whey protein 20-25 g/meal:
Highest leucine concentrationEasy to digest + fast absorptionCombine with meals, do not replace them
② Creatine 5 g/day:
Older adults: ↑ muscle mass + strength + cognition (Forbes 2023 + Candow 2014 meta)Best paired with strength trainingExcellent cost ($0.10/day)See atlas creatine + creatine/mechanism L4
③ HMB (β-hydroxy β-methylbutyrate) 3 g/day:
Anti-catabolic > pro-synthesisStrong indication in older adults with acute illness / bed rest / malnutrition (Deutz 2013, Bear 2019 meta)See atlas hmb story
④ Vitamin D:
Deficiency (< 30 ng/mL) is independently associated with sarcopenia800-2000 IU/day → improved strength + reduced falls (Bischoff-Ferrari 2009 meta)Multiple atlas vitamin-d L4s
⑤ Mg + Zn:
Common deficiencies in older adults; supplementation supports mitochondrial function + protein synthesis
Not recommended:
"Senior miracle pills" (marketing bundles) — read the ingredients individuallyOTC DHEA / testosterone — high risk, requires physician evaluationGrowth hormone — FDA labelling prohibits anti-ageing indication, carcinogenic risk
The problem:
GLP-1 class produces 15-20% weight loss over 12-24 monthsBut 25-40% of that loss is muscle, not just fat (Wilding 2021 STEP-1 and follow-up analyses)Older adults with high GLP-1 exposure → accelerated sarcopenia + ↑ falls / fracture risk
Why GLP-1 reduces muscle:
Appetite suppression → substantial protein-intake dropReduced overall food → insufficient MPS triggeringRapid weight loss itself causes muscle loss (all rapid-weight-loss methods do)Older-adult anabolic resistance worsens the problem
"Muscle-Centric Medicine" (Lyon 2025 ACSM consensus):
GLP-1 + high protein + strength training = mandatory bundleProtein target: 1.6-2.0 g/kg/day while on GLP-1 (toward the upper bound in older adults) — ⚠️ applies only when eGFR ≥ 60 mL/min/1.73m²; CKD stage 3a-5 needs nephrology-led stratification by eGFR (0.6-0.8 g/kg + high-quality protein); see the "protein and renal function" sub-page in this storyStrength training 2-3×/weekDon't just watch the scale — monitor muscle change by DXA / BIA
Same problem with "caloric restriction" weight loss (not only GLP-1):
Any rapid weight loss is accompanied by muscle lossOlder adults are especially vulnerableVLCD (DiRECT 850 kcal/day) should be used cautiously in older adults — high muscle-loss risk
Ideal weight-loss strategy (older / middle-aged with sarcopenia risk):
Slow (0.5-1 kg/month, not 1 kg/week)Protein 1.6-2.0 g/kgStrength training 2-3×/weekDXA every 3-6 months to monitor muscle + fatGLP-1 under supervision, not OTC
Weight loss ≠ fat loss:
"Weight loss" reads the scale (water + muscle + fat mixed)"Fat loss" reads body composition (DXA / BIA / waist)Fat loss + muscle gain + stable weight = healthy goal
Senior supplement toolkit (with evidence):
① Whey protein 20-25 g/meal:
Highest leucine concentrationEasy to digest + fast absorptionCombine with meals, do not replace them
② Creatine 5 g/day:
Older adults: ↑ muscle mass + strength + cognition (Forbes 2023 + Candow 2014 meta)Best paired with strength trainingExcellent cost ($0.10/day)See atlas creatine + creatine/mechanism L4
③ HMB (β-hydroxy β-methylbutyrate) 3 g/day:
Anti-catabolic > pro-synthesisStrong indication in older adults with acute illness / bed rest / malnutrition (Deutz 2013, Bear 2019 meta)See atlas hmb story
④ Vitamin D:
Deficiency (< 30 ng/mL) is independently associated with sarcopenia800-2000 IU/day → improved strength + reduced falls (Bischoff-Ferrari 2009 meta)Multiple atlas vitamin-d L4s
⑤ Mg + Zn:
Common deficiencies in older adults; supplementation supports mitochondrial function + protein synthesis
Not recommended:
"Senior miracle pills" (marketing bundles) — read the ingredients individuallyOTC DHEA / testosterone — high risk, requires physician evaluationGrowth hormone — FDA labelling prohibits anti-ageing indication, carcinogenic risk
数字 · 掉的有多少是肌肉
一两年 (12-24 月) 能让人瘦掉 15-20% 的体重。问题出在——掉下去的那部分里, 有 25-40% 是肌肉 (Wilding 2021 STEP-1 那批研究和后续分析都看到了)。本来就在往肌少症走的老人, 再叠上这种药, 等于给流失踩了脚油门, 跌倒、骨折的风险跟着往上冒。顺带说, 这个坑不是减肥针独有的——任何靠猛节食快速掉秤的方式都一样会连肌肉一起减, 老人尤其扛不住。像 DiRECT 那种一天只吃 850 kcal 的极低热量方案 (VLCD), 老年人就要格外小心。
实操 · 打针期间怎么护肌肉
以肌肉为中心具体怎么做 (Lyon 2025 ACSM 共识):用药期间蛋白往上加, 目标 1.6-2.0 g/kg/天 (老年人取上限)。⚠️ 但这句话有个硬前提: 只对肾功能还正常 (eGFR ≥ 60 mL/min/1.73m²) 的人成立。已经到慢性肾病 (CKD) 3a-5 期的, 反过来要在肾内科指导下按肾功能一档档往下降 (降到 0.6-0.8 g/kg, 并挑优质蛋白)——这条别自己拿主意, 细节见本幕的蛋白与肾功能那一页每周练 2-3 次力量别只盯着体重秤: 秤上掉了不代表掉的是脂肪, 得靠 DEXA 或体成分仪 (BIA) 看肌肉到底有没有丢
怎么减 · 老人版
那老人、或者中年就有肌少风险的人, 想减该怎么减? 大方向是慢: 一个月掉 0.5-1 kg 就好, 别追一周 1 kg; 蛋白照样吃到 1.6-2.0 g/kg; 每周 2-3 次力量; 每 3-6 个月用 DEXA 查一次, 看肌肉和脂肪各变了多少; 真要用减肥针, 也得在医生看着的情况下用, 不是自己买来打 (别当 OTC 用)。这里其实藏着一个很多人没分清的区别: 减肥不等于减重。 体重秤量的是一锅乱炖——水、肌肉、脂肪全掺在里头; 真正该看的是身体成分 (DEXA、BIA、腰围), 是脂肪掉了、肌肉还在。减掉脂肪、长了点肌肉、体重没怎么变, 这才是健康的目标, 别被秤上那个数字骗了。
补剂 · 蛋白、肌酸与 HMB
补剂这块, 真有证据的就那么几样, 挑出来说:乳清蛋白, 每餐 20-25 g: 亮氨酸浓度最高, 好消化、吸收快; 记住它是配着正餐吃, 不是拿它替代吃饭肌酸, 每天 5 g: 老人吃它能同时长肌肉、长力气, 连脑子都可能沾光 (Forbes 2023、Candow 2014 meta), 配着力量训练效果最好, 一天才一毛钱 ($0.10), 性价比极高 (细节看 atlas 的 creatine 和 creatine/mechanism L4)HMB (β-羟基 β-甲基丁酸, 亮氨酸的一种代谢物), 每天 3 g: 它的强项是拦着别让肌肉分解, 而不是催着合成; 老人生急病、卧床、营养不良时特别对症 (Deutz 2013、Bear 2019 meta, atlas hmb 故事讲过)
补剂 · 维生素 D 和微量元素
维生素 D: 缺 D 的人 (血里低于 30 ng/mL) 更容易肌少, 每天补 800-2000 IU 能帮着长力气、少摔跤 (Bischoff-Ferrari 2009 meta, atlas 里有好几个 vitamin-d L4)镁 (Mg) 和锌 (Zn): 老人常缺, 补上能给线粒体和蛋白合成搭把手别碰的那几样
也有几样得泼冷水、不推荐: 那种老人神药丸式的营销组合, 拆开一样样看清成分再说; DHEA、睾酮的 OTC (非处方) 产品风险不小, 必须医生评估过才碰; 至于生长激素, FDA 明令禁止拿它当抗衰用, 还带着致癌风险, 别碰。Chapter 5
Decision tree
Decision tree
"How should I prevent / treat sarcopenia?" by life stage:
20-30 y/o:
The foundation you build now matters most — peak muscle massProtein 1.2-1.6 g/kgStrength training 2-3×/weekAdequate calories + sleepThese habits over 60 years determine your muscle mass at 80
30-50 y/o:
Already losing 0.5-1% muscle per year — it has startedMaintain protein at 1.2-1.5 g/kgStrength training is essential (most 30-50 y/o do aerobic only)Prevent sedentariness + maintain core stability + balance
50-65 y/o:
The acceleration window — menopause in women + slow T decline in menProtein ≥ 1.2-1.5 g/kgStrength training 2-3×/weekTrack annual muscle change (DXA / BIA once)Monitor vitamin D + Mg + Zn
65+ y/o (clinical prevention + treatment phase):
Screening: grip + gait speed + sit-to-stand (at home)Protein 1.2-1.6 g/kg, 25-40 g per mealStrength training 2-3×/week (senior-friendly modifications)Vitamin D 800-2000 IU/day + sunlightWhey + creatine + HMB for cost-effective supplementationAnnual comprehensive assessment + fall prevention
Already diagnosed with sarcopenia:
Geriatrics / rehabilitation consultIntensified nutrition + intensified training simultaneouslyHMB 3 g/day strong indicationglucagon-like peptide-1: A gut hormone released after eating that makes you feel full and helps lower blood sugar. / weight loss paused or cautiously evaluatedReassess at 6 months — most patients improve
Self-check (any age):
Sit-to-stand from a chair, no hands, 5 times in < 11 sWalk 10 m in < 12 s (gait speed ≥ 0.8 m/s)Grip: men ≥ 28 / women ≥ 18 kg (Asian standard; dynamometers are inexpensive)Climb 4 floors without getting out of breathAnything below threshold → take note
Special situations:
① Acute illness / before surgery:
Intensify protein for 2 weeks (1.5-2 g/kg)HMB + whey reservesPost-op early mobilisation + early rehab trainingOne week of bed rest in an older adult → 10-15% muscle loss
② Severe chronic disease:
Cancer / chronic HF / chronic lung disease / CKDNutrition counselling + protein + training + supplementation"Sarcopenic obesity" (high BMI + low muscle mass) is a hidden diagnosis
③ ICU / prolonged bed rest:
1 week loses 10-25% muscleEarly passive + active trainingIntensified nutrition
Pitfalls to avoid:
"Less meat at old age": wrong, accelerates sarcopenia"Protein hurts kidneys": fine for healthy kidneys; check eGFR"Older adults can't train": wrong, 80+ can still train (Fiatarone)"Walking is enough": wrong, without strength training muscle keeps melting away"Just take supplements": ineffective alone; must combine with training + real food"Just lose weight": wrong, older adults must preserve muscle first, then cut fat
Atlas connections:
protein story + protein/muscle L4 (leu-mechanistic target of rapamycin: The cell's master 'grow / build' switch — turned on by enough protein and resistance training.)vitamin-d story + multiple L4shmb + creatine + collagen-peptidesperimenopause + andropause (hormones)endocrine/metabolic-syndrome (metabolism)fall-prevention (future addition)
Atlas position: sarcopenia is not "the fate of ageing" — it is a degeneration preventable starting at 30. "Can I climb stairs / carry groceries / live independently at 80?" = "Did I do strength training + eat enough protein today?" Today is not too late, but every year you wait is more so.
20-30 y/o:
The foundation you build now matters most — peak muscle massProtein 1.2-1.6 g/kgStrength training 2-3×/weekAdequate calories + sleepThese habits over 60 years determine your muscle mass at 80
30-50 y/o:
Already losing 0.5-1% muscle per year — it has startedMaintain protein at 1.2-1.5 g/kgStrength training is essential (most 30-50 y/o do aerobic only)Prevent sedentariness + maintain core stability + balance
50-65 y/o:
The acceleration window — menopause in women + slow T decline in menProtein ≥ 1.2-1.5 g/kgStrength training 2-3×/weekTrack annual muscle change (DXA / BIA once)Monitor vitamin D + Mg + Zn
65+ y/o (clinical prevention + treatment phase):
Screening: grip + gait speed + sit-to-stand (at home)Protein 1.2-1.6 g/kg, 25-40 g per mealStrength training 2-3×/week (senior-friendly modifications)Vitamin D 800-2000 IU/day + sunlightWhey + creatine + HMB for cost-effective supplementationAnnual comprehensive assessment + fall prevention
Already diagnosed with sarcopenia:
Geriatrics / rehabilitation consultIntensified nutrition + intensified training simultaneouslyHMB 3 g/day strong indicationglucagon-like peptide-1: A gut hormone released after eating that makes you feel full and helps lower blood sugar. / weight loss paused or cautiously evaluatedReassess at 6 months — most patients improve
Self-check (any age):
Sit-to-stand from a chair, no hands, 5 times in < 11 sWalk 10 m in < 12 s (gait speed ≥ 0.8 m/s)Grip: men ≥ 28 / women ≥ 18 kg (Asian standard; dynamometers are inexpensive)Climb 4 floors without getting out of breathAnything below threshold → take note
Special situations:
① Acute illness / before surgery:
Intensify protein for 2 weeks (1.5-2 g/kg)HMB + whey reservesPost-op early mobilisation + early rehab trainingOne week of bed rest in an older adult → 10-15% muscle loss
② Severe chronic disease:
Cancer / chronic HF / chronic lung disease / CKDNutrition counselling + protein + training + supplementation"Sarcopenic obesity" (high BMI + low muscle mass) is a hidden diagnosis
③ ICU / prolonged bed rest:
1 week loses 10-25% muscleEarly passive + active trainingIntensified nutrition
Pitfalls to avoid:
"Less meat at old age": wrong, accelerates sarcopenia"Protein hurts kidneys": fine for healthy kidneys; check eGFR"Older adults can't train": wrong, 80+ can still train (Fiatarone)"Walking is enough": wrong, without strength training muscle keeps melting away"Just take supplements": ineffective alone; must combine with training + real food"Just lose weight": wrong, older adults must preserve muscle first, then cut fat
Atlas connections:
protein story + protein/muscle L4 (leu-mechanistic target of rapamycin: The cell's master 'grow / build' switch — turned on by enough protein and resistance training.)vitamin-d story + multiple L4shmb + creatine + collagen-peptidesperimenopause + andropause (hormones)endocrine/metabolic-syndrome (metabolism)fall-prevention (future addition)
Atlas position: sarcopenia is not "the fate of ageing" — it is a degeneration preventable starting at 30. "Can I climb stairs / carry groceries / live independently at 80?" = "Did I do strength training + eat enough protein today?" Today is not too late, but every year you wait is more so.
年轻和中年 · 攒家底的阶段
20-30 岁: 这是肌肉量的顶峰, 现在攒下的家底最值钱。蛋白吃到 1.2-1.6 g/kg, 每周练 2-3 次力量, 热量和睡眠都给够。这些习惯要陪你走 60 年——你 80 岁时身上还剩多少肌肉, 很大程度上是现在这几年打的底。30-50 岁: 从这时候起, 肌肉已经在每年悄悄掉 0.5-1% 了, 流失开始了。蛋白维持在 1.2-1.5 g/kg, 力量训练这时变得不能省——可偏偏大多数三四十岁的人只做有氧, 从不碰铁。同时别久坐, 顾着点核心稳定和平衡。
加速期与老年 · 防和治
50-65 岁: 进入加速期——女性绝经、男性睾酮 (T) 缓慢下滑, 都在这一段。蛋白不低于 1.2-1.5 g/kg, 每周 2-3 次力量, 每年用 DEXA 或体成分仪 (BIA) 查一次, 盯着肌肉的年度变化; 维生素 D、镁 (Mg)、锌 (Zn) 也顺便监测。65 岁以上 (这时候是临床上又防又治的阶段): 先做筛查——握力、走路速度、坐下起立, 在家就能测 (具体标准见下面的自查)。蛋白吃到 1.2-1.6 g/kg、每顿 25-40 g; 每周 2-3 次力量训练, 用老人友好的版本; 维生素 D 每天 800-2000 IU, 再加上晒太阳; 乳清、肌酸、HMB 这几样性价比高的补剂可以加上; 每年做一次综合评估, 同时做好防跌倒。
已经确诊 · 自查与扭转
已经确诊肌少症的: 找老年科、康复科会诊, 营养和训练同时强化; HMB 每天 3 g 在这时候很对症; 减肥针、减重的事先停下, 或非常谨慎地评估; 6 个月后再复查——好消息是, 大多数人是能扭转回来的。不管你多大, 有几个动作在家就能自查, 不达标就该上点心:
坐在椅子上, 不用手撑, 连着起立坐下 5 次, 看能不能 < 11 秒完成走 10 米 < 12 秒 (换算过来, 步速要到 0.8 m/s)握力: 男的 ≥ 28 kg、女的 ≥ 18 kg (亚洲标准, 握力计网上就能买)一口气爬 4 层楼不喘
特殊时候 · 生病、手术、卧床
还有几种特殊时候, 要额外上心。一是生急病、或要做手术前: 提前把蛋白强化 2 周 (加到 1.5-2 g/kg), 备上 HMB 和乳清; 术后越早下床、越早做康复越好——老人只要卧床 1 周, 肌肉就能掉 10-15%, 掉得触目惊心。
二是得了慢性重病的: 像肿瘤、慢性心衰、慢性肺病、慢性肾病 (CKD) 这些, 需要营养师介入, 蛋白、训练、补剂一起配合。这里要特别提防一种藏起来的诊断——肌少性肥胖 (高 BMI + 低肌量): 体重、BMI 看着都正常, 其实是肌肉少、脂肪多 (这个坑本幕下面有一整页专门讲)。
三是进了 ICU 或长期卧床: 肌肉 1 周能掉 10-25%, 要尽早做被动和主动训练, 同时强化营养。
避雷 · 最常踩的几个错
最后集中避几个雷, 都是老人身上最常见的错:老了就该少吃肉: 错, 这是在给肌少症踩油门蛋白伤肾: 肾好的人没事, 关键看 eGFR老人不能练: 错, 80+ 岁照样练得动 (Fiatarone)走路就够了: 错, 不练力量, 肌肉照样一路流失靠保健品就行: 单吃没用, 必须配上训练和真正的饭先减肥再说: 错, 老人得先把肌肉保住, 再谈减脂
想接着往深里看, atlas 上这几座岛是连着的: protein 和它的 muscle L4 (讲亮氨酸怎么点火)、vitamin-d、hmb、creatine、collagen-peptides、讲激素的 perimenopause 和 andropause、讲代谢的 metabolic-syndrome, 防跌倒那块 (fall-prevention) 以后会补上。
Sarcopenic obesity · the missed dx
Sarcopenic obesity (SO) = coexistence of low muscle mass + high body-fat percentage. It is one of the most severely misdiagnosed metabolic diseases because weight / BMI "look normal."Why it is routinely missed:
BMI 23 + body fat 40% (women) or 28% (men) → BMI "normal," but body composition is pathologicalThe scale cannot tell muscle from fatTOFI (thin outside fat inside) — high visceral fat + sarcopenia + apparently leanThis is a more common diagnostic blind spot in Asian populations on the atlas (Asians at the same BMI have higher visceral-fat ratio than Europeans — see atlas microplastics chapter)
Diagnostic criteria (EASO 2022 consensus):
Low muscle mass: low DXA appendicular muscle index (women < 5.5 kg/m², men < 7.0 kg/m²) or BIA equivalent+ high body-fat percentage: women > 35-40%, men > 25-30%+ functional decline: low grip + slow gait
Clinical consequences (worse than pure sarcopenia or pure obesity):
Higher CVD risk (dual hit)High prevalence of T2D / NAFLD / metabolic syndrome↑↑ falls + fracture risk (obese + weak)Disability + premature death (1.5-2× vs normal)Poor tolerance of surgery / chemotherapy
At-risk groups:
Postmenopausal women (50+)After GLP-1 / weight-loss / very-low-calorie weight loss (fat lost with muscle)Chronic disease + sedentariness + high UPF diet70+ y/o with "normal" BMI but inactive for years
Why SO risk is rising in the glucagon-like peptide-1: A gut hormone released after eating that makes you feel full and helps lower blood sugar. era:
Wegovy / Ozempic / Mounjaro produce rapid weight loss~ 25-40% of weight lost is lean mass (not only fat)Without paired strength training → fat loss with substantial muscle loss → SO riskLong-term, the body "looks slimmer" but function + metabolic status may worsen
Diagnosis + treatment:
Self-check (without DXA):
Grip + 5-times sit-to-stand timing + gait speed (as above)Waist / height ≥ 0.5 (central-obesity marker, more accurate than BMI)Scales with BIA: read body-fat percentage rather than weight only
Formal diagnosis:
DXA (whole-body + appendicular muscle differentiation)BIA (Inbody / Tanita professional versions)
Treatment (priority order):
1. Strength training 2-3×/week + progressive overload — strongest single intervention
2. Protein 1.2-1.6 g/kg/day + 25-40 g per meal + leucine 2.5 g
3. Gentle caloric deficit (300-500 kcal) — not aggressive dieting
4. Aerobic exercise (limits excess fat accumulation)
5. Adequate vitamin D + Mg + Zn
6. Stop smoking + limit alcohol + adequate sleep
7. Manage chronic conditions (T2D / HTN / depression)
Not recommended:
Very-low-calorie diet (VLCD < 800 kcal): accelerates sarcopenia, more reboundAerobic alone without strength: reduces muscle-fat ratioMeal replacements / shakes as staples: insufficient protein + lack of fiber
Difference between "losing weight" and "losing fat":
"Weight loss" (lower scale weight) = muscle + fat + water reduction"Fat loss while preserving muscle" = fat reduction with muscle maintained → scale drops slowly but metabolism is healthierThe real goal is the second. Read scale + waist + body-fat % in combination — do not be fooled by a single "weight" number
Atlas connections: protein/muscle L4 + endocrine/metabolic-syndrome + exercise (FITT strength training = single strongest ageing intervention) + T2D (GLP-1 era sarcopenia warning) + perimenopause (E2 withdrawal + accelerated muscle loss).
References · 9
- Cruz-Jentoft, A. J., & Sayer, A. A. (2019). Sarcopenia. The Lancet, 393(10191), 2636-2646. 10.1016/S0140-6736(19)31138-9
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- Deutz, N. E., Bauer, J. M., Barazzoni, R., Biolo, G., Boirie, Y., Bosy-Westphal, A., et al. (2014). Protein intake and exercise for optimal muscle function with aging: ESPEN. Clinical Nutrition, 33(6), 929-936. 10.1016/j.clnu.2014.04.007
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- American College of Sports Medicine. (2018). ACSM's Guidelines for Exercise Testing and Prescription (10th ed.). Wolters Kluwer. www.acsm.org/education-resources/books/guidelines-exercise-testing-prescription
- Phillips, S. M. (2017). Current concepts and unresolved questions in dietary protein requirements and supplements in adults. Frontiers in Nutrition, 4, 13. Includes critical appraisal of HMB / leucine metabolite supplementation — small added effect on top of adequate dietary protein in trained adults. 10.3389/fnut.2017.00013
- Wilding, J. P. H., Batterham, R. L., Calanna, S., Davies, M., Van Gaal, L. F., Lingvay, I., et al. (2021). Once-weekly semaglutide in adults with overweight or obesity (STEP-1). New England Journal of Medicine, 384(11), 989-1002. 10.1056/NEJMoa2032183
- Bear, D. E., Langan, A., Dimidi, E., et al. (2019). β-Hydroxy-β-methylbutyrate and its impact on skeletal muscle mass and physical function in clinical practice: a systematic review and meta-analysis. The American Journal of Clinical Nutrition, 109(4), 1119-1132. 10.1093/ajcn/nqy373
- Deutz, N. E. P., Pereira, S. L., Hays, N. P., et al. (2013). Effect of β-hydroxy-β-methylbutyrate (HMB) on lean body mass during 10 days of bed rest in older adults. Clinical Nutrition, 32(5), 704-712. 10.1016/j.clnu.2013.02.011