Scanned muscle mass failed a major health test that strength and walking speed passed

Key takeaways

• In a 2020 analysis of more than 18,000 older adults, weak grip and slow walking predicted falls, hip fractures, mobility problems and death, while muscle mass measured by DXA scan did not consistently predict them¹².
• Which test you use changes who gets labeled: in one Norwegian study, a chair-stand test flagged more than three times as many adults with sarcopenia as a grip test did³.
• The 2025–2030 Dietary Guidelines set a protein goal of 1.2 to 1.6 grams per kilogram of body weight a day, up from the 0.8-gram RDA, but a 2026 expert perspective said the evidence doesn’t support one higher target for everyone⁶⁷⁹.
• For adults with chronic kidney disease at risk of getting worse, international kidney guidelines advise staying under 1.3 grams per kilogram a day, below the top of the new federal range¹².
• The American Diabetes Association’s 2026 Standards say that for people with diabetes on obesity drugs or after weight-loss surgery, muscle-strengthening exercise may help hold on to lean mass⁸.

In 2020, a research consortium set out to define sarcopenia, the loss of muscle that comes with age¹. Its funders included the National Institute on Aging and the Foundation for the National Institutes of Health¹.

The team pooled data from eight long-term studies of 13,421 men and 4,828 women living in their communities². Then an independent international panel voted on 13 statements built from the work¹.

Muscle mass, measured by the X-ray body scan called DXA, didn’t make the cut. It wasn’t consistently linked to falls, broken hips, mobility problems or death¹². A weak grip and a slow walking pace were¹².

That finding matters now that federal protein goals have risen⁶. Muscle does matter: it’s where much of your blood sugar goes, as our insulin sensitivity article explains, and lifting can lower blood pressure, as our resistance training article shows.

But research keeps finding that what your muscle can do counts more than how much of it a scan sees. And the way muscle is measured changes who gets labeled.

Experts now define muscle loss by what muscle can do

Two groups set today’s definitions. Our article on preserving muscle covers how Europe’s 2019 update, called EWGSOP2, put strength first. Here are the yardsticks it uses³:

• Grip strength: under 27 kilograms for men or 16 for women counts as low.
• Chair stands: taking more than 15 seconds to stand up from a chair five times counts as low.
• Low strength alone means “probable” sarcopenia. Low muscle mass in the arms and legs confirms it.

The NIA-funded Sarcopenia Definitions and Outcomes Consortium went further in 2020. It defined sarcopenia by weakness and slowness and left scanned muscle mass out¹.

Its cutoffs differ from Europe’s. Grip under 35.5 kilograms for men or 20 for women, and walking slower than 0.8 meters per second, flagged higher risk². People below a cutoff had roughly 1.2 to 3 times the odds or risk of the bad outcomes studied, and people who were both weak and slow fared worst².

Industry helped pay for the consensus meeting. Besides federal grants, Abbott Nutrition, Astellas and Cytokinetics supported the conference¹.

The test you choose changes who has sarcopenia

Definitions aren’t just paperwork. They decide who hears the word “sarcopenia.”

In 2020, a European team applied the old and new European definitions to 2,256 older adults in eight groups, from community members to hospital patients⁴. Under the 2010 version, 31.9% of the men had sarcopenia. Under EWGSOP2, 12.0% did⁴.

For women, the share rose slightly, from 4.9% to 6.1%⁴. The lower grip cutoffs explained the drop in men, the authors said⁴.

The choice of strength test matters, too. In Norway’s Tromsø Study, researchers tested 3,498 adults ages 40 to 84 in 2015 and 2016³.

• Using grip, 1.3% had probable or confirmed sarcopenia³.
• Using chair stands, 4.4% did, more than three times as many by our math³.
• At age 80 and older, the gap widened: 8.4% by grip and 20.4% by chair stands³.

The two tests barely agreed on who was weak, and they flagged people with different body types³. The authors said it’s unclear whether one test can stand in for the other³.

How much muscle you have is harder to pin down than how strong you are. A companion article on body composition explains how scans and smart scales estimate muscle, and how far off they can be.

Sarcopenic obesity: weak muscle inside a larger body

In 2022, two European societies, ESPEN and EASO, issued a joint definition of sarcopenic obesity⁵. They describe it as excess body fat together with low muscle mass or poor muscle function⁵.

The idea is simple. A person in a larger body can carry plenty of weight and still have weak legs. The scale and BMI hide that.

The consensus, signed by 38 authors, lays out these steps⁵:

1. Screen people with a high BMI or waist size who also show signs of low muscle mass or function, such as symptoms, risk factors or a positive questionnaire.
2. Test muscle function first, then body composition.
3. Confirm when excess fat and low muscle mass show up together.
4. Stage it: stage I without complications, stage II with problems tied to body composition or weak muscle.

The panel noted that without one shared definition, studies had produced inconsistent counts of how common it is⁵. It urged new research to test whether the criteria predict health outcomes⁵.

A companion article on weight and metabolic health covers the 2025 push to diagnose obesity with more than BMI.

How much protein? Federal and diabetes guidance differ

The Recommended Dietary Allowance (RDA) for healthy adults is still 0.8 grams of protein per kilogram of body weight a day⁷. The 2025–2030 Dietary Guidelines, released in January 2026, aim higher: 1.2 to 1.6 grams per kilogram, with protein prioritized at every meal⁶⁷.

Not every guideline group agrees. The American Diabetes Association’s Standards of Care in Diabetes—2026 say there’s no evidence that eating more or less protein than the amount recommended for the general public, typically 0.8 to 1.5 grams per kilogram, improves health in people with diabetes⁸. Research hasn’t settled the ideal amount, they add, so goals should fit each person’s usual eating⁸.

What the numbers mean for a 180-pound adult, about 82 kilograms, by our math:

Benchmark	Grams per kilogram	Grams a day at 82 kg
RDA7	0.8	About 65
Dietary Guidelines goal6	1.2 to 1.6	About 98 to 131
Kidney guideline ceiling for adults with CKD at risk of worsening12	Under 1.3	Under about 106

Nutrition scientists have pushed back. In a July 2026 perspective in The Journal of Nutrition, Stefan Pasiakos and colleagues credited the guidelines’ focus on quality protein foods. They said this range can help with weight management in people with overweight or obesity⁹.

But Pasiakos said the evidence falls short of supporting one higher-protein target for all Americans across the lifespan, and the authors called for research on how the range fits different groups⁹. Tufts University’s Dariush Mozaffarian told the Associated Press that more protein mainly helps people doing strength training¹⁰.

Stanford’s Christopher Gardner raised a different worry: sales of protein-boosted packaged foods are climbing even as the guidelines push whole foods, which he expects will confuse shoppers¹⁰. Our protein article covers food sources, and our protein powder article covers the products.

Spreading protein across meals: a sensible habit with thin proof

Older adults tend to load their protein into the evening meal¹¹. Does that pattern cost muscle?

A Danish team tested it in 24 healthy adults ages 65 to 80, published in 2023¹¹. Both groups ate the same total protein. One spread it evenly, about 22 grams at each main meal. The other ate about 11 grams at breakfast and lunch and about 44 grams at dinner¹¹.

With the even pattern, the whole body held on to more protein after breakfast and lunch, mostly because it broke down less¹¹. But muscle-building rates over nine hours didn’t differ¹¹. The study lasted one measured day after a 10-day lead-in, and it didn’t measure muscle size or strength¹¹.

The trial was co-funded by Danish Crown Ingredients, a meat company, and the authors reported no conflicts¹¹.

Our rating: Promising but early. Protein at each meal is easy and fits the new guidelines⁶. Just don’t expect timing to do the work of total protein and training.

Kidneys set the ceiling for some people

Higher protein targets aren’t for everyone. Kidney Disease: Improving Global Outcomes (KDIGO), the international kidney guideline group, updated its chronic kidney disease (CKD) advice in 2024¹².

For adults with CKD stages 3 to 5, KDIGO suggests 0.8 grams per kilogram a day, about the RDA¹². For adults with CKD at risk of getting worse, it advises against going above 1.3 grams per kilogram¹². Both rest on limited evidence, and the 0.8 advice carries a low grade, 2C¹².

There’s a twist. KDIGO also says older adults with CKD who are frail or have sarcopenia may need higher protein and calorie targets¹². That balance is personal, so it belongs in a conversation with your kidney doctor or a dietitian.

Too little is risky, too. The ADA says cutting protein below 0.8 grams per kilogram isn’t recommended for people with diabetes-related kidney disease, because it doesn’t slow kidney decline and may raise the risk of malnutrition⁸.

Losing weight without losing strength

When you lose weight, some of what you lose isn’t fat. With GLP-1 weight-loss drugs, lean mass can make up 15% to 40% of the total, the ADA said in 2025¹³. Lean mass is everything that isn’t fat, so it includes more than muscle. Our muscle article covers the figures from the semaglutide trials.

The ADA’s 2026 Standards address it head-on. For people with diabetes taking obesity medicines or after weight-loss surgery, muscle-strengthening exercise may help maintain lean body mass, a C-grade recommendation⁸. During planned weight loss, the ADA also advises watching protein and nutrient intake alongside regular resistance training⁸.

Drug companies are testing ways to protect muscle. In the BELIEVE trial, funded by Eli Lilly, 507 adults with obesity took semaglutide, an experimental antibody called bimagrumab, both, or a placebo¹³¹⁴¹⁵. After 72 weeks¹⁴:

• Semaglutide alone: 15.7% of body weight lost; 71.8% of the loss was fat.
• Bimagrumab alone: 10.8% lost, all of it fat; lean mass rose 2.5%.
• Both together: 22.1% lost; 92.8% of it was fat, per Pennington and the ADA¹³¹⁴, though one trade report put that share at 92.2%¹⁵.

By our math, that’s about 28% of the loss coming from non-fat tissue on semaglutide alone, versus about 7% with the combination.

The trade-offs are real. Bimagrumab brought acne and muscle spasms¹⁴. In the groups given bimagrumab alone, 14% to 21% stopped because of side effects, far more than with semaglutide or the combination¹⁵.

Some people had temporary rises in liver and muscle enzymes¹⁵. Bimagrumab remains investigational¹⁴.

The muscle check and protect plan

We built this plan from the studies and guidelines above. The tests are the same ones researchers use, but a home result isn’t a diagnosis.

Check: three simple tests

Test	How	What research cutoffs mean	When to see a clinician
Five chair stands	Time five stands from a chair; our physical function article explains how to do it safely	Over 15 seconds is EWGSOP2’s low-strength mark3	If you’re over 15 seconds, ask about a sarcopenia check13
Grip strength	Ask to have it measured with a hand gauge at a checkup	Low: under 27 kg (men) or 16 kg (women) in Europe; under 35.5 kg or 20 kg in the U.S. analysis23	Ask what your number means for your age and size12
Walking speed	Usual pace over a short, timed course; covered in our walking speed article	Under 0.8 meters per second flagged higher risk2	Raise it if you’ve slowed or started to fall12

Protect: matched to your situation

Your situation	Protein step	Training step	Talk to your care team if…
Most adults	Protein foods at each meal, from plants, fish, dairy, eggs or meat; the guideline goal is 1.2 to 1.6 g/kg6	Resistance work on 2 or 3 nonconsecutive days a week, as ADA advises for people with diabetes8	You have diabetes or high heart risk; ADA advises a careful history and a slow start8
Losing weight, with or without a GLP-1 drug	Keep protein foods steady while eating less8	Keep strength training going through the weight loss8	You’re on an obesity drug or had surgery; ask for a protein and strength plan8
Larger body with weak legs or grip	Same food-first steps6	Strength training 2 or 3 days a week8	Your BMI or waist is high and your legs or grip feel weak; ask about sarcopenic obesity testing5
Chronic kidney disease	Don’t raise protein on your own; stay under 1.3 g/kg if your CKD may worsen12	Strength training after a careful check8	Before any protein change; ask about a dietitian812
Older, frail or recently ill	With CKD, guidelines say higher targets may suit frail older adults12; our protein article covers targets after 65	Start supervised; our muscle article has a plan by age	After a hospital stay; our hospital muscle article covers recovery

If measuring your body or counting protein starts to feel compulsive, step back. The National Alliance for Eating Disorders runs a weekday helpline staffed by licensed therapists at 1-866-662-1235. In a crisis, call or text 988.

This plan asks for no device or pill. That fits a core natural-health belief: the body builds what you ask of it. Muscle answers to use and real food, and the best tests of it are things you do every day, like rising from a chair.

What the evidence shows

Claim	Evidence level	What it rests on
Weak grip and slow walking predict falls, fractures and death	Strong evidence	Pooled data from eight cohorts of more than 18,000 older adults12
Muscle mass on a DXA scan predicts those outcomes as well as strength does	Evidence says no, or unsafe	Not consistently linked in the same pooled data12
Every adult benefits from 1.2 to 1.6 g/kg of protein	Not enough evidence	Experts say the evidence doesn’t support one target for all89
Spreading protein evenly across meals preserves muscle	Promising but early	Short metabolic studies; no muscle-size outcome11
Strength training helps keep lean mass during drug-assisted weight loss	Promising but early	ADA C-grade recommendation8
Bimagrumab protects muscle on semaglutide	Promising but early	One company-funded phase 2 trial; side effects and dropouts1415
Keeping protein near 0.8, and under 1.3 g/kg, protects kidneys in CKD	Promising but early	Guideline advice resting on limited evidence12

Questions readers ask

The bottom line

Muscle matters, but the evidence keeps pointing to function over size. Grip strength, chair stands and walking speed track your future health better than a scan’s muscle count, and the test you pick changes who gets labeled.

Eat protein foods at each meal, train for strength two or three times a week, and protect that work when you lose weight. If your kidneys aren’t healthy, talk with your clinician before you follow the new 1.2-to-1.6 protein goal.

Related reading

• Frail 90-year-olds nearly tripled their strength, proof that muscle responds at any age
• Who needs the new protein goal of up to twice the RDA
• After 65, walking speed predicts survival about as well as your health history
• Weights once sent blood pressure past 400, but done right, lifting lowers it
• Most People Don’t Need Protein Powder. Here’s How to Pick One if You Do

Sources

1. Bhasin S, Travison TG, Manini TM, et al. “Sarcopenia Definition: The Position Statements of the Sarcopenia Definition and Outcomes Consortium.” Journal of the American Geriatrics Society, 2020;68(7):1410–1418 (Vrije Universiteit Amsterdam record, including funding). research.vu.nl
2. Cawthon PM, Manini T, Patel SM, et al. “Putative Cut-Points in Sarcopenia Components and Incident Adverse Health Outcomes: An SDOC Analysis.” Journal of the American Geriatrics Society, 2020;68(7):1429–1437 (CDC Stacks record). stacks.cdc.gov
3. Tromsø Study researchers. Analysis of EWGSOP2 sarcopenia prevalence by grip strength and chair stands in adults aged 40–84, Tromsø 7 (2015–16). BMC Geriatrics, 2020 (article s12877-020-01860-w). link.springer.com
4. Van Ancum JM, Alcazar J, Meskers CGM, Nielsen BR, Suetta C, Maier AB. “Impact of using the updated EWGSOP2 definition in diagnosing sarcopenia: A clinical perspective.” Archives of Gerontology and Geriatrics, 2020;90:104125 (Vrije Universiteit Amsterdam record). research.vu.nl
5. Donini LM, Busetto L, Bischoff SC, et al. “Definition and Diagnostic Criteria for Sarcopenic Obesity: ESPEN and EASO Consensus Statement.” Obesity Facts, 2022;15(3):321–335 (University of Geneva open archive). archive-ouverte.unige.ch
6. Elsayed S, Nelson M. “Dietary Guidelines for 2025–2030: Recommendations From the USDA and HHS.” American Family Physician, 2026;114(1):98–100. aafp.org
7. Pradhananga N, Hildebrand D, Gabel C, Evans C. “The New Dietary Guidelines for Americans 2025–2030.” Oklahoma State University Extension, FCS-3629, June 2026. extension.okstate.edu
8. American Diabetes Association Professional Practice Committee. “5. Facilitating Positive Health Behaviors and Well-being to Improve Health Outcomes: Standards of Care in Diabetes—2026.” Diabetes Care, 2026;49(Suppl 1) (continuing-education copy, Weitzman Institute). education.weitzmaninstitute.org
9. News-Medical. “Experts review evidence behind updated protein intake recommendations” (on Pasiakos SM, et al., “Perspectives on the Protein Recommendations in the 2025–2030 Dietary Guidelines for Americans,” The Journal of Nutrition, 2026, via an American Society for Nutrition release). July 24, 2026. news-medical.net
10. Aleccia J, Associated Press. “New diet guidelines say to double up on protein but nutrition experts are wary.” The Independent, January 2026 (via inkl). inkl.com
11. Agergaard J, Justesen TEH, Jespersen SE, Tagmose Thomsen T, Holm L, van Hall G. “Even or skewed dietary protein distribution is reflected in the whole-body protein net-balance in healthy older adults: A randomized controlled trial.” Clinical Nutrition, 2023;42(6):899–908 (University of Birmingham repository). doi.org
12. Prasad P, Vishwakarma K, Sethi J. “The KDIGO 2024 CKD Guidelines: part 2” (summary of the Kidney Disease: Improving Global Outcomes 2024 guideline). NephJC, May 21, 2024. nephjc.com
13. American Diabetes Association. “New GLP-1 Therapies Enhance Quality of Weight Loss by Improving Muscle Preservation.” Press release, June 23, 2025. professional.diabetes.org
14. Pennington Biomedical Research Center. “Combination GLP-1 Therapy Shows Fat Mass Loss While Preserving Lean Mass in Adults with Obesity” (on Heymsfield SB, et al., Nature Medicine, 2026; trial funded by Eli Lilly and Company). March 5, 2026. pbrc.edu
15. Drug Topics. “Results Show Bimagrumab With Semaglutide Achieve Substantial Weight Reduction.” March 9, 2026. drugtopics.com