How people get it: Sold over the counter.
The basics
What it is
Bioelectrical impedance is one way to measure muscle mass in studies of muscle loss.
How it works
A measure from bioelectrical impedance called phase angle is thought to reflect water distribution and body cell mass.
What the research has found so far
- A review of studies found that phase angle was lower in people with sarcopenia, which is loss of muscle mass and strength.
- A review of studies found that sarcopenia was more common in people with low phase angle.
- The review's authors say more studies are needed to know how useful phase angle is for spotting sarcopenia.
On smart scales and aging, PubMed lists 571 trials in people, 2,934 studies that watched people over time, 56 animal and lab studies. See the counts and searches
Capped at stage 2: the large trials this search finds use body-composition scales to measure results, such as an obesity prevention program (PubMed 21041593); they don't test smart scales themselves.
A stage shows how far research has got, not whether it will work for you. How stages work
Questions to ask your doctor
- Would smart scales be useful for me, and what should I do with the readings?
- Which type or model would you trust, and how do I use it so the readings are accurate?
- Could I bring it to an appointment to check it against your equipment?
- How often should I share the results with you, and which numbers should make me call?
This is general information gathered from the sources listed, not medical advice. Talk to your doctor before starting anything new.
Devices you can buy
Read from each maker's page. The research stage is for this kind of device, not proof that a particular model is accurate or right for you.
What experts say
No expert views collected yet. Each one we add names the person and links to where they said it.
What others are writing
Recent articles about Smart scales from health journalists, hospitals and universities. We link to them; we don't write or endorse them.
Device of the month: Body-weight scale - Harvard Health ↗
“Many smart scales also feature a technology called bioelectrical impedance analysis. It sends a small current through your bare feet to try to estimate your body fat, muscle mass, and water weight.”
The article says smart scales often use bioelectrical impedance analysis, whose body composition readings are not well established as accurate.
Recent research
New studies that mention Smart scales appear here after the morning update.
Trials
ClinicalTrials.gov lists 1,287 registered trials that mention Smart scales, for any condition (the count in The science below). Here we show the ones about aging. See them all ↗
The science
Counted from PubMed and ClinicalTrials.gov on Oct 30, 2026, using one search for Smart scales in relation to aging. Each link opens the exact search.
- Randomized trials in people
- 330 search ↗
- Large trials (multicenter or phase 3)
- 36 search ↗
- Phase 3 trials
- 3 search ↗
- Trials in people
- 571 search ↗
- Studies that watched people over time
- 2,934 search ↗
- Animal and lab studies
- 56 search ↗
- Registered trials
- 1,287 search ↗
PubMed search used
("smart scale*"[tiab] OR "bioelectrical impedance"[tiab] OR "body composition scale*"[tiab] OR "Electric Impedance"[mh]) AND (aging[tiab] OR ageing[tiab] OR longevity[tiab] OR healthspan[tiab] OR "older adults"[tiab] OR "older people"[tiab] OR elderly[tiab] OR "Aged"[mh])
Counts are search results, so they include some records that only mention Smart scales. How we count
Cite or share this page
Longevity Progress. (n.d.). Smart scales: Research stage and evidence. Retrieved October 30, 2026, from https://longevityprogress.com/treatments/smart-scales
<iframe src="https://longevityprogress.com/embed/stage/smart-scales" title="Smart scales: research stage on Longevity Progress" width="340" height="72" style="border:0" loading="lazy"></iframe>
The badge shows this treatment's current research stage and links back here. It updates by itself when the stage changes.