DEXA gives the more accurate single reading. InBody gives the more useful repeat reading. InBody usually reads a few points off DEXA, but in a 2019 study its four-week change matched DEXA's. Book a DEXA if you want one reference number. Take the same InBody, under the same conditions, every month if you want to know whether your training is working.
- DEXA is the reference method. InBody is the practical tool for tracking change month to month.
- The two usually disagree by a few body fat points, and the direction flips depending on who is scanned.
- Between two InBody scans, a change smaller than about 2.1 to 2.7 body fat points may be noise.
- InBody's manual lists prep rules, from no food for 3 to 4 hours to a 20-minute warm-up in winter.
- Cash DEXA runs from about $40 at mobile events to $150 at a clinic near Southdale.
How InBody and DEXA each measure you
DEXA, short for dual-energy X-ray absorptiometry and sometimes written DXA, reads your body with X-rays. You lie on a table while a scanner arm passes over you, sending two low-dose beams at different energies. Bone, fat, and lean tissue absorb those beams differently, so the machine separates all three, region by region.
InBody uses a small electrical current instead, with no X-rays involved. The InBody 570 training manual says the device sends that current at three frequencies: 5, 50, and 500 kHz. Water-rich lean tissue carries the current easily and fat resists it, and the device builds its estimate from the difference.
The printout reports skeletal muscle mass, body fat percentage, visceral fat level, and total body water. It also breaks lean and fat down by segment: arms, legs, and trunk. That's what it measures. It doesn't diagnose anything, and our coaches won't read it as if it does.
Because InBody reads you through your body's water, anything that shifts your water can shift the number.
InBody vs DEXA: how far apart do they read?
Usually a few percentage points of body fat, and not always in the same direction. Here's what five validation studies found.
| Study | Who was scanned | What InBody read, compared with DEXA |
|---|---|---|
| McLester et al., 2020 | 67 adults from the general population | Lower body fat and higher fat-free mass on all three InBody models tested |
| Antonio et al., 2019 | 41 exercise-trained adults, average age 33 | Body fat 3.9 points lower (22.5% vs 26.4%), but the four-week change matched |
| Lee et al., 2018 | 507 Korean adults, average age 63.7 | Whole-body muscle mass 2.28 kg higher |
| Buch et al., 2022 | 84 adults with type 2 diabetes, average age 71.4 | Body fat 1.46 points higher (38.44% vs 36.98%) |
| Nakagata et al., 2026 | 1,617 adults aged 65 to 84 | Arm and leg lean mass about 9.2% lower |
The Antonio row is the one to study. InBody averaged 22.5% body fat for those 41 adults, while DEXA averaged 26.4%. Over four weeks, though, DEXA measured an average fat loss of 1.1 kg and InBody measured 1.2 kg. The difference wasn't statistically significant.
That's the whole case for InBody. It can miss the starting number and still track the change.
The three studies with an average age over 60 show why no single rule holds. InBody read whole-body muscle high in the 507 adults averaging 63.7 years, more so in men and in people with a lower BMI. It read arm and leg lean mass low in the 1,617 adults aged 65 to 84, by 7.0% in men and 10.7% in women. In the 84 adults averaging 71.4 years, it read body fat higher than DEXA, the opposite of the 2019 and 2020 studies.
The practical rule: an InBody number and a DEXA number don't belong on the same chart. Compare each one only with itself.
DEXA has error too
DEXA earns reference status on repeatability. In a 2011 study of 52 adults, repeat scans varied by 0.82% for total fat mass and 0.5% for lean mass. That still doesn't make it error-free.
The International Society for Clinical Densitometry sets the standard in its 2023 official positions. The minimum acceptable precision for an individual technologist is 3% for total fat mass and 2% for both lean mass and percent fat. The person positioning you on the table is part of the measurement. The same positions list DEXA's visceral fat estimate as optional and say its clinical utility is "currently uncertain."
Machines disagree with each other, too. A 2024 study scanned 926 postmenopausal women, average age 72.9, on two different DEXA brands. Lean mass differed by 1,293.7 grams, or 3.1%. Percent fat differed by 1.1 points, and the visceral fat estimate by 22.9%.
Switching DEXA machines between scans can mislead you as badly as switching methods. If you buy DEXA scans, buy them on the same machine.
What throws off an InBody reading?
Water, food, exercise, and winter cold can all move the number. Water is the one to start with.
In a 2022 study, 20 young adults drank water at 11 mL per kilogram of body weight, about 807 mL on average. Their InBody fat mass rose about 0.9 kg right away and about 1.3 kg 60 minutes later. Body fat percentage climbed about 1.5 points. Standing for 65 minutes lowered lean mass by about 0.8 kg.
A large glass of water read as more than a kilogram of fat.
The InBody 570 manual lists this prep before a test:
- Hydrate well the day before.
- Stand upright for at least 5 minutes before the scan.
- Skip caffeine on test day.
- Don't eat for 3 to 4 hours beforehand.
- Use the restroom first.
- Don't exercise for 6 to 12 hours beforehand.
- No alcohol for 24 hours beforehand.
- Don't test right after a shower or sauna.
- Skip the lotion.
- In winter, warm up for 20 minutes first.
That last rule could have been written for Minnesota. Walk in from a York Avenue parking lot in January, and the manual wants you warm for 20 minutes before you step on.
The manual also says to avoid testing if you're pregnant, menstruating, or have a pacemaker or other life-sustaining medical implant. If you're pregnant or have an implant, talk with your physician before choosing any scan. If you're menstruating, test another week.
The fix for everything else is consistency: same time of day, same prep, same machine, every month.
Where to get a DEXA scan in the Twin Cities
Search "DEXA scan Minneapolis" or "body composition scan near me," and the DEXA options fall into four categories. Listed cash prices run from about $40 to $150.
Boutique scan clinics. One a few minutes from Southdale lists a single DEXA at $150 and sells multi-scan packages.
Mobile providers. These advertise scans from about $40 when they're running events locally. Availability comes and goes, so check before you plan around one.
Imaging centers. One lists a cash DEXA at about $111, but a provider referral is required. The listing doesn't specify the scan type, so ask whether you'd get a body composition report or bone density only.
University labs. These sometimes scan the public or research volunteers. Call before assuming you can book one.
At $150 a scan, monthly DEXA tracking adds up fast, even with packages.
Hospital DEXA ordered by a physician is a different test: a bone density scan. Medicare Part B covers a bone mass measurement once every 24 months, or more often if medically necessary, when you meet the criteria. You pay nothing if your doctor accepts assignment. It answers a question about bone, not about muscle and fat.
If bone is part of your question, start with your physician. We covered strength training and bone density for women over 50 separately.
Which body composition scan should you get?
If you're training, get the InBody and repeat it every month. A DEXA is worth adding only if you want an occasional reference number, repeated on the same machine.
InBody scan accuracy against DEXA matters less than InBody's consistency against itself. In the 2020 McLester study, InBody was repeatable to within about 1 point of body fat across visits one to three days apart. The same study calculated a minimum difference of 2.12 to 2.73 points. A change smaller than that between two scans may be measurement noise, not progress.
So judge the trend, not the single scan. Body composition change typically shows over 8 to 12 weeks, and monthly scans on one device turn that window into a line you can read. The useful question is what changed since last month, not what the number is today.
Members get an InBody scan every month. A coach reads each one against the member's own program in small group personal training, where sessions are capped at six people.
You don't need a membership for the InBody scan. Book a free InBody scan. Once you have a printout, here's how to read your InBody results.
Start with a scan and a plan
Your Starting Point Session covers all of this in one visit. A coach assesses how you move, talks through your goals and history, runs your InBody scan, and builds a plan around you. You'll get a membership recommendation with straightforward pricing and no pressure to decide on the spot. Alloy Personal Training Edina Southdale opened in October 2026. Book your Starting Point Session, and if you want first pick of session times, look at Founding Membership.
This article is general fitness information, not medical advice. Talk with your physician before starting a new exercise program, especially if you have a diagnosis, a recent surgery, or activity restrictions.
Frequently asked questions
Is an InBody scan accurate?
It's consistent, which is what matters for tracking. A 2020 study of 67 adults found InBody repeatable to within about 1 percentage point of body fat between visits. Against DEXA it usually reads body fat a few points lower. One exception: in a 2022 study of 84 adults with type 2 diabetes averaging 71.4 years, it read 1.46 points higher.
Which is better, InBody or DEXA?
DEXA is better for one reference number, and InBody is better for monthly tracking. In a 2019 study of 41 trained adults, InBody's four-week change in fat mass matched DEXA's with no statistically significant difference. Whichever you choose, repeat it on the same machine.
How much does a DEXA scan cost in the Twin Cities?
Listed cash prices for a body composition DEXA run from about $40 at mobile scan events to $150 at a boutique clinic near Southdale. One imaging center lists a cash DEXA at about $111 but requires a provider referral. A physician-ordered bone density scan is a separate test. Medicare Part B covers it once every 24 months, or more often if medically necessary, when you meet the criteria.
Who should not take an InBody test?
InBody's manual says to avoid testing if you're pregnant, menstruating, or have a pacemaker or other life-sustaining medical implant. If you're pregnant or have an implant, talk with your physician before choosing any body composition scan. If you're menstruating, schedule the scan for another week.