The trend is what I care about; individual weeks are obviously noise.
I would like to know whether this claim survives contact with evidence.
If the answer is "nobody has tested that", I would like that stated so I can stop looking.
How well supported is this claim?
The short version: strength first, mass second, physical performance to grade severity. That ordering is deliberate and recent.
Appendicular skeletal muscle mass index below roughly 7.0 kg/m² in men and 5.5 kg/m² in women is the usual confirmatory threshold on DXA.
| Method | Measures | Sensitive to | Least significant change |
|---|---|---|---|
| DEXA | Three-compartment by attenuation | Hydration, positioning | ~2–3 % regional lean |
| BIA (consumer) | Impedance, modelled | Hydration, food, temperature | Not usable at this timescale |
| Air displacement | Two-compartment by density | Lung volume, hair, clothing | ~1–2 % fat mass |
| Tape and scale | Circumference, mass | Technique | Surprisingly usable as a trend |
Age-related loss runs at roughly one per cent of muscle mass per year after the fifth decade, accelerating later, so a superimposed deficit-related loss compounds an existing trajectory.
The current operational definition comes from the revised European consensus, which moved strength ahead of mass as the primary criterion.
Higher protein per meal with age, because of anabolic resistance.
Aggregated, published test results and vendor ratings built from submitted batches. Methodology stated, dataset browsable, no listing fees.
Browse resultsThe condition is defined against population reference values, so absolute numbers matter more than personal trends here.
The European working group definition uses low grip strength or low chair-stand performance as the entry criterion, confirms with low appendicular skeletal muscle mass adjusted for height, and grades severity by gait speed or a short physical performance battery.
Concretely, resistance training remains effective into the ninth decade; the response is slower and smaller than in younger adults but it is not absent, which is the single most useful fact in this tag.
The caveat is that this is a clinical diagnosis and self-diagnosis from a home scale is not possible; bioimpedance in particular is unreliable at these thresholds.
Resistance training works at every age studied. Slower, smaller, still real.
edited 19 Feb 2025 by a_lindgren — added a caveat about sampling
Answer first: sarcopenia is defined by low muscle strength with low muscle quantity, and function rather than mass is the primary criterion in the current definitions.
Gait speed below about 0.8 metres per second is the usual severity marker and is the measure most strongly associated with adverse outcomes.
To be exact about it, common grip-strength cut-points are below about 27 kilograms for men and 16 for women, though the thresholds vary by definition and by population reference set.
Anabolic resistance in older adults is established from stable-isotope feeding studies and is why per-meal protein thresholds are higher with age.
Strength first, mass second, performance for severity. That is the definition.
The honest answer is that rapid weight loss in an older adult without resistance training is a genuine risk factor, and that the mitigation is entirely unglamorous.
Protein requirements are generally considered higher in older adults — often quoted at 1.2 to 1.5 g/kg for maintenance — because of anabolic resistance rather than because of increased losses.
Nothing here is medical advice.
Grip strength is the cheap screening test and it is genuinely informative.
Grip strength is the standard screening measure because it is cheap, repeatable and predicts outcomes better than mass does.
Sarcopenic obesity is the combination that matters in this population: adequate or high total mass with low muscle mass, which no scale detects and which a body-mass index actively conceals.
Sarcopenic obesity is invisible on a scale. Measure or you will not see it.
edited 21 Apr 2025 by forty_two_c — added the placebo-arm figures
Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.