DexaFit Seattle

The protein math for protecting lean mass during a GLP-1 protocol runs 0.8 to 1.4 grams per pound of lean mass.

Most people are calculating from their total body weight. That denominator is wrong, and the gap compounds during a caloric deficit.

The correct number comes from your lean mass. A DEXA scan gives you that number. Once you have it, hitting your protein floor meal by meal is the next problem to solve.

The Sheet Pan Meal Maker does that part. Enter your lean mass and it calculates your personal protein floor, then builds a complete meal around it — protein, veggies, fat, optional carb — calibrated to your physiology, not a population average.

DEXA gives you the target. The app helps you hit it.

Comment BLOCKS below and I'll send it to your DMs.

The clinical question surrounding GLP-1 medications has shifted.

Twelve months ago, most of the conversation centered on efficacy: how much weight patients lose, how long it holds, what side effects show up.

Those questions haven't gone away, but among longevity-focused clinicians, a more specific and more uncomfortable question has moved to the center.

What's the composition of what's actually being lost?

The data is in.
Across major GLP-1 trials, lean mass accounts for roughly 25 to 45 percent of total weight lost. The number varies by drug and protocol. Tirzepatide drives greater relative lean mass loss than semaglutide at equivalent time points, despite producing greater total weight loss overall.

A 2026 analysis of over 670,000 real-world GLP-1 users identified a specific pattern researchers call the Depletive GLP-1 metabotype, defined as losing more than 20 percent of total body weight along with more than 5 percent lean mass. That pattern showed up in 10.3 percent of tirzepatide users and 6.7 percent of semaglutide users.

Here's the downstream consequence of that pattern, stated plainly.

Muscle is metabolically expensive tissue. Resting metabolic rate reflects, in part, how much lean mass you carry. Lose a meaningful portion of it and your resting caloric burn drops. The deficit that was producing results starts requiring more restriction to hold the same effect, and the protocol gets less efficient as the structural foundation shrinks beneath it.

Lean mass is also the primary mechanical signal keeping bone mineral density from declining, so when it drops rapidly, bone loses its main stimulus at exactly the moment age-related bone loss is already building.

GLP-1 medications work. The protocol around them just needs structural monitoring to work well.

This outcome is adaptive, not inevitable. Adequate protein intake, calibrated to lean mass rather than total body weight, changes the body's calculus about what to shed during aggressive caloric restriction. Resistance training gives the body a signal that its structural capacity is still needed. Both inputs require knowing the starting point.

A DEXA scan before a GLP-1 protocol gives you the lean mass baseline needed to calculate precise protein targets.

Serial scans during the protocol tell you whether your composition is shifting in the direction you intend. Without that data, the number on the scale tells you nothing about what's actually happening to your structural chassis.

The number is going down. The question worth asking is which number, exactly.

P.S. — The protein target that protects lean mass during a GLP-1 protocol runs 0.8 to 1.4 grams per pound of lean mass, calibrated to lean mass, not total body weight. Without a DEXA scan, lean mass is unknown, so the calculation stays an estimate instead of a prescription.

Once you have that number, the Sheet Pan Meal Maker turns your protein floor into actual meals built around it:

Try the Sheetpan meal maker
Link in comments

Lean mass loss during GLP-1 therapy is an adaptive response to a severe caloric deficit — and adaptive responses can be influenced.

The body sheds muscle when it is in a large energy deficit and receives no signal that the load-bearing capacity of that tissue is still required. Provide those signals consistently, and the body has a reason to hold onto the structural foundation it built.

Two specific inputs determine whether that happens. Protein intake needs to be calibrated to lean mass rather than total body weight — the clinical target for protecting muscle during a GLP-1 protocol runs roughly 0.8 to 1.4 grams per pound of lean mass. Without a DEXA scan, lean mass is unknown, which means that calculation is an estimate rather than a prescription. The second input is resistance training — the mechanical stimulus that tells the body its structural capacity is still necessary. Both inputs require knowing the starting point.

The DEXA scan provides it.

Tirzepatide produces greater total weight loss than semaglutide across trials and real-world studies.

It also produces greater lean mass loss.

A 2026 analysis of over 670,000 real-world GLP-1 users found tirzepatide was associated with greater relative lean body mass loss than semaglutide at every measured time point across 12 months. A separate pattern called the Depletive GLP-1 metabotype — defined as losing more than 20 percent of total body weight with more than 5 percent lean mass loss — occurred significantly more often in tirzepatide users than semaglutide users, at 10.3 percent versus 6.7 percent.

The composition of what gets lost determines whether a GLP-1 protocol strengthens the chassis or quietly compromises it. Total weight is one number. What that number is made of is the clinical question worth asking.

A DEXA scan before and during your protocol is the only way to track which kind of weight you are actually losing.

Millions of people are losing weight on GLP-1s right now. Most of them have no idea what they're actually losing.

When the body sheds weight fast under a severe caloric deficit, lean muscle mass goes with it. Clinical trials on semaglutide and tirzepatide consistently show 25 to 45 percent of total weight lost can come from lean tissue, depending on drug, dose, and individual response. That number moves around a lot. The scale doesn't care.

Here's what that lean mass loss sets in motion. Resting metabolic rate drops because muscle is metabolically expensive to maintain. Bone density loses its primary mechanical stimulus. Protein requirements climb at exactly the moment GLP-1-driven appetite suppression makes hitting those targets harder. And the whole time, the scale reads progress.

A DEXA scan is the clinical tool that separates fat loss from muscle loss. Without one, GLP-1 patients are tracking a single number with zero visibility into what's happening underneath it.

If you're on a GLP-1 or planning to start one, get scanned. Know what you're actually losing.

𝗧𝗵𝗲 𝗮𝘁𝗵𝗹𝗲𝘁𝗲𝘀 𝗮𝘁 𝘁𝗵𝗶𝘀 𝗪𝗼𝗿𝗹𝗱 𝗖𝘂𝗽 𝗵𝗮𝘃𝗲 𝗯𝗲𝗲𝗻 𝘀𝘁𝗿𝘂𝗰𝘁𝘂𝗿𝗮𝗹𝗹𝘆 𝗮𝗻𝗮𝗹𝘆𝘇𝗲𝗱 𝗶𝗻 𝘄𝗮𝘆𝘀 𝗺𝗼𝘀𝘁 𝗽𝗲𝗼𝗽𝗹𝗲 𝗻𝗲𝘃𝗲𝗿 𝘄𝗶𝗹𝗹 𝗯𝗲.

Box-to-box midfielders covering 13 kilometers a match at 80 percent of max heart rate. Position-specific body fat targets. Bone mineral density up to 18 percent higher than non-athletes the same age and BMI. Bilateral asymmetry data tracked by performance staff because it predicts injuries before the athlete feels a thing.

That data doesn't just describe elite soccer players. It describes exactly what DEXA measures ... and what it reveals about anyone willing to look.

Swipe through to see what the structural profile of a World Cup player actually looks like, and what it means for the rest of us.

☀️🏃‍♀️🧊🧖‍♂️ SUMMER SATURDAYS AT ALKI BEACH

Join us for Run. Plunge. Sauna. — a monthly morning of movement and recovery, hosted with , , and .

📍 Alki Beach
📅 June 27 | July 25 | August 22
⏰ 9AM

The format: a casual 5K run or walk, a cold plunge in the Sound, and a sauna session to close things out.

Run/walk is free. Sauna access is $20 (that's $15 off the usual rate).

Link to sign up is in the 1st comment

Tag a friend who'd love a morning like this. Link in bio to register.

𝗧𝘄𝗼 𝗽𝗼𝘂𝗻𝗱𝘀.

That's approximately where the research draws the line on visceral fat — the threshold above which cardiometabolic risk climbs measurably, independent of your total body fat percentage or how lean you appear.

Visceral fat wraps around your internal organs, sits deep in the abdominal cavity, and is highly metabolically active. Research published in Circulation established it as an independent predictor of cardiovascular disease, type 2 diabetes, and metabolic syndrome — even in people whose total body fat falls within normal ranges. A person can carry meaningful visceral fat volume while looking completely lean in the mirror. Their scale reads nothing useful. Their BMI says nothing at all.

The only accurate non-invasive way to measure visceral fat volume is imaging — and of the available options, DEXA is the clinical standard that's actually accessible outside a hospital. It separates visceral fat from all other tissue, gives you a precise number in pounds, and puts it in context against population norms.

Most health snapshots don't include this number. Which means most people are managing their metabolic risk without the variable most likely to drive disease over the next decade.

By the time your doctor orders your first bone density scan, you've had roughly 30 years of decline with no baseline.

Standard guidelines recommend that first scan at 65. Peak bone mass occurs in your late 20s to early 30s. The math on that gap is not complicated.

After peak, bone responds to the demands placed on it. Load-bearing exercise, adequate protein, and the right nutritional inputs can slow the decline. Reduce those inputs, and the skeleton adapts accordingly — in the wrong direction.

Worth noting: osteoporosis has long been framed as a women's issue. That framing is outdated. Approximately 2 million men in the US currently have osteoporosis, with another 16 million carrying low bone mass and elevated fracture risk. One in four men over 50 will experience an osteoporosis-related fracture in their lifetime. The suspected driver is exactly what you'd predict — more sedentary childhoods, fewer hours of load-bearing physical activity across the lifespan, more years spent at a desk. Bone responds to mechanical demand. Two generations of systematically reduced demand are producing the results you'd expect.

The stakes are specific: low bone mineral density increases fracture risk, alters joint loading mechanics, and compounds the lean mass losses that drive structural decline over time. Bone that has been neglected for decades takes years to meaningfully change. The window for intervention is not infinite.

A DEXA scan measures bone mineral density directly, at the same clinical sites used in osteoporosis screening. Establishing that baseline in your 30s or 40s gives you something to work from. Waiting until 65 gives you documentation of what has already happened.

The research community has spent the last ten years reclassifying muscle as a longevity organ. The fitness industry hasn't caught up yet.

Lean muscle mass now ranks among the strongest predictors of all-cause mortality in the literature, outperforming BMI as a health indicator at virtually every age. The mechanism is direct: muscle regulates glucose metabolism, supports joint integrity, generates the bone loading stimulus that keeps skeletal density from declining, and provides the reserve capacity that determines whether aging becomes frailty or stays functional.

The condition of losing it is called sarcopenia. It begins earlier than most people expect, accelerates through the 40s and 50s without deliberate intervention, and is almost never screened for until it has already become a clinical problem.

The clinical test that measures lean mass precisely is a DEXA scan — direct measurement by region, with bilateral breakdown included. No estimates, no proxies.

If you have not established a lean mass baseline, you are managing one of the most consequential health variables entirely blind.

Book your DEXA scan: Seattle.DexaFit.com