DEXA vs InBody Singapore: Which Body Composition Test?

InBody is enough for 80% of people, 80% of the time. DEXA is the reference standard for body composition analysis, but at about SGD 129 to SGD 370 a scan in Singapore it is only worth it for a specific list of cases. The question is not which machine is more accurate. The question is which one answers what you are actually trying to learn, and where an InBody scan in Singapore fits before you pay for the reference test.

TL;DR

What InBody actually measures

InBody is a multi-frequency bioelectrical impedance analyser. You stand on a scale, your bare feet on metal electrodes, and you grip a pair of hand electrodes. The machine sends a low-amperage alternating current through your body at several frequencies, measures how much each frequency is resisted, and uses that resistance to estimate fat mass, lean mass, total body water, and a Skeletal Muscle Index. Thirty to sixty seconds, depending on the model. About SGD 35 to 45 on its own in Singapore, and often included in a studio trial. Once you have a printout in hand, our walkthrough of how to read your InBody result sheet decodes it number by number.

What it actually measures is impedance. What you read on the printout is an estimate derived from that impedance via a population-fitted equation. The headline numbers, body fat percent and lean mass, repeat very closely from scan to scan, but they sit consistently off DEXA. Antonio and colleagues (2019) compared the InBody 770 against DEXA before and after a 4-week diet: the average change in the group matched, but the InBody read fat mass lower and fat-free mass higher than DEXA, and varied much more from person to person. McLester and colleagues (2020) tested three InBody models (230, 720 and 770) in healthy adults and reported test-retest intraclass correlations of 0.98 or higher for body fat percent and fat mass, and 0.99 or higher for fat-free mass. All three still underestimated body fat and overestimated fat-free mass against DEXA.

The catch is real-world conditions. InBody readings are sensitive to hydration, recent meals, and recent training. A recent meal, a training session or a change in hydration can each move the reading by around a kilogram, and not always in the direction you would guess. InBody's own guidance is to test before exercise and two to three hours after eating. In studio conditions across hundreds of repeated measurements, the practical day-to-day variation we see at Catalyst is around 1.5 to 2.5 percentage points on body fat percent, which sets the floor for how small a change you can trust between scans.

What DEXA actually measures

DEXA is dual-energy X-ray absorptiometry. You lie flat on a table, an arm passes over your body at two different X-ray energies, and the difference in absorption between the two energies separates lean tissue from fat tissue from bone. The whole-body scan itself takes about 3 minutes on one current Hologic model and 7 to 13 minutes on a GE Lunar iDXA, depending on body size; Singapore General Hospital allows 10 to 15 minutes for the whole procedure. In Singapore, a private body composition scan costs about SGD 129 to SGD 370 with GST, at a screening clinic, a dedicated body-composition clinic or an imaging centre. Bone density of hip and spine is usually a separate scan with a separate price.

DEXA is the reference standard, which means most bioimpedance validation studies report their numbers against a DEXA comparator. This is not the same as saying DEXA is perfect. It still depends on operator positioning, scanner calibration, and the device manufacturer's tissue-discrimination algorithms. Scanners from different manufacturers disagree too: when the same women were scanned on a GE Lunar iDXA and a Hologic Horizon A within an hour, total lean mass differed by about 3 percent and trunk lean mass by about 12 percent. The reference standard has its own error band.

The radiation dose is small. A whole-body DEXA scan delivers roughly 0.001 to 0.008 millisievert, depending on the scanner. That is about a day of natural background radiation or less, against the worldwide average of 2.4 millisievert a year, and between one-sixth and one-fiftieth of the cosmic radiation on a transatlantic flight. It is also well below a chest X-ray, at about 0.1 millisievert.

Four numbers both tests give you, and the one only DEXA delivers

Both InBody and DEXA report total body fat percent, total lean mass, a Skeletal Muscle Index (arm and leg lean mass per unit height squared), and an estimate of visceral fat, although on DEXA the visceral fat estimate needs extra software that not every clinic runs. For ordinary tracking these four numbers are what you actually use. Tracked over time, the two methods agree on the direction of change for a group, but for one person the agreement is only moderate: in a 7-week study the concordance of individual changes was about 0.5 for both fat mass and fat-free mass. Track change on one machine, and never compare a reading from one machine with a reading from the other.

The number only DEXA gives you reliably is regional lean mass. DEXA reports the lean mass in your left arm, right arm, left leg, right leg, and trunk as separate values. This matters in three specific scenarios: rehabilitation after a unilateral injury where you want to track left-versus-right symmetry over months, longitudinal monitoring of appendicular skeletal muscle for sarcopenia diagnostics in adults over 60, and athletes optimising power-to-weight for a sport where leg-specific lean mass distribution matters (cycling, sprinting, single-leg-dominant events). InBody reports segmental impedance, which is not the same thing. The segmental number is a derived estimate, not a direct measurement.

DEXA also gives you bone mineral density at the same scan. That is a separate clinical decision-making input, particularly for post-menopausal women in Singapore where osteoporosis screening is part of HPB-recommended preventive care for adults aged 65 and above.

When an InBody scan in Singapore is enough

For most adults in Singapore tracking body composition over months and years, InBody is the right tool. The reasons are practical, not technical.

Repeatability beats absolute precision when your goal is to monitor change. If you scan on the same InBody machine at the same time of day, in the same hydration state, every 8 to 12 weeks, a change in lean mass of about 2 kilograms or more stands out from the machine's own error. Smaller changes do not: the minimum detectable difference for fat-free mass on current InBody models is about 1.6 to 2.3 kilograms. A single DEXA scan does not give you change. It gives you a static reference point you might never repeat because of cost. Our fat loss calculator sets the expectation for that window: it estimates how much fat you should realistically lose across 8 to 12 weeks, so a scan either confirms the plan or tells you something is off.

Most of what you need to know about your body composition is well-served by an InBody scan: are you carrying excess visceral fat, is your lean mass appropriate for your height, is your Skeletal Muscle Index above or below the Asian Working Group for Sarcopenia threshold for your sex, and is your hydration in a normal range. These are the questions InBody answers well. Skeletal Muscle Index together with Waist-to-Height Ratio explains most of the body-composition signal that maps to longevity.

When DEXA is worth the SGD premium

DEXA earns its cost in five situations. First, suspected sarcopenia in adults 60 and above where the AWGS 2019 diagnostic workflow benefits from a reliable Skeletal Muscle Index measurement and the regional lean mass distribution informs treatment priorities. Second, post-surgical rehabilitation where left-versus-right leg lean mass asymmetry tracks the rehabilitation timeline and InBody's segmental estimate is not sensitive enough. Third, athletes optimising power-to-weight where leg-specific lean mass distribution materially changes training prescription. Fourth, establishing a baseline before starting long-term medication that affects body composition: GLP-1 receptor agonists where you want to track lean-mass preservation against the documented muscle-loss risk, hormone replacement therapy, long-term glucocorticoid courses. Fifth, when you are also screening for osteoporosis and one scan can answer two questions.

For anyone outside those five cases, the SGD 129 to SGD 370 a DEXA scan costs does not return clinically meaningful information that an InBody scan plus a Jamar grip dynamometer plus a stability assessment would not already give you. The four numbers that actually predict how well you age are not all body-composition numbers.

How we use InBody at Catalyst

InBody is one of four measurements in the Catalyst 4-Pillar Healthspan Assessment we run in our Manulife Tower studio in Singapore's CBD. The other three are cardiorespiratory fitness via a 3-minute step test, grip strength via a Jamar hydraulic dynamometer, and stability via a Y-Balance lower-quarter protocol. The four pillar scores combine into a single Healthspan Score we retest every 16 weeks.

The reason InBody is in our protocol and not DEXA is that we want repeatability across hundreds of clients and dozens of retests per year. Sending every client to a radiology clinic for a DEXA scan every quarter is not realistic. Standing on an InBody for 60 seconds is. The scan is one of four signals we triangulate, not a single number we hand the client and call done. A standalone InBody reading without a strength measurement and a cardiorespiratory measurement is incomplete information about how well a body is ageing.

If a client's InBody scan flags a Skeletal Muscle Index in the AWGS sarcopenia range, or a left-right segmental asymmetry that does not resolve over 8 to 12 weeks of training, we refer out for DEXA. That is the right division of labour. InBody is the screening instrument. DEXA is the diagnostic instrument when the screening flags something. For the broader population context, about 1 in 3 Singaporeans aged 60 and above met sarcopenia criteria in the Yishun Study, which is why the InBody-then-DEXA pathway exists at all.

Frequently asked questions

Q. Where can I get a body analysis in Singapore?

A body analysis in Singapore usually means one of two things: a DEXA scan at a clinic or imaging centre, or an InBody bioimpedance reading at a gym or studio. For tracking training progress over time, a consistent InBody body composition analysis is practical and affordable; for a precise clinical baseline, DEXA is the stronger option. At Catalyst, body composition is the first of the four pillars we measure, so a body analysis here sits inside a full read of how well you are ageing rather than as a standalone number.

Q. How much does an InBody scan cost in Singapore?

In Singapore, a standalone InBody scan costs about SGD 35 to 45 at a training studio or clinic, and many studios include it in a trial session or first assessment. The variation comes from whether the scan includes a coach interpreting the result or only a printed sheet. A standalone scan with no interpretation has limited value.

Q. How much does a DEXA scan cost in Singapore?

A private whole-body DEXA scan in Singapore costs about SGD 129 to SGD 370 with GST, and a doctor's review is often charged on top. Bone density is usually sold as a separate scan, at about SGD 129 to SGD 155, and screening packages that list both often let you pick only one. Check whether the report includes regional lean mass distribution; not every provider reports it by default. For provider-by-provider prices and which scan to ask for, see our DEXA scan Singapore guide.

Q. Where can I get a DEXA scan in Singapore?

DEXA scans are offered at dedicated body-composition clinics, health-screening clinics and private imaging centres. DexaFit Singapore (Oxley Tower) specialises in DEXA body-composition scanning; ATA Medical, a health-screening clinic, arranges the scan at a partner imaging centre in Orchard. We name these as genuine starting points, not a ranking; confirm current pricing and whether regional lean mass is reported before booking.

Q. Is the DEXA radiation dose safe?

Yes. A whole-body DEXA scan delivers roughly 0.001 to 0.008 millisievert, depending on the scanner. That is about a day of natural background radiation or less, against the worldwide average of 2.4 millisievert a year, and between one-sixth and one-fiftieth of the cosmic radiation on a transatlantic flight. It is also well below a chest X-ray, at about 0.1 millisievert.

Q. Can I track body composition at home without either machine?

You can buy a consumer-grade bioimpedance scale in Singapore that reports body fat percent, from about SGD 30 for a basic model to over SGD 200 for a premium one. The output drifts more than InBody and absolute accuracy is poor, but change over time within the same device is informative if you weigh yourself under the same conditions each morning. For longevity-focused tracking the more useful at-home measurement is waist-to-height ratio: a tape measure at the navel divided by your standing height. A ratio above 0.5 carries independent metabolic risk regardless of what any body composition scan tells you. For a free, no-equipment proxy you can run before booking any scan, our waist-to-height ratio calculator flags visceral-fat risk against the 0.5 boundary using only a tape measure.

Q. Where can I get an InBody test in Singapore?

InBody scans are offered at premium personal training studios, wellness clinics, and some gyms across Singapore. At Catalyst Performance, an InBody scan is one of the four measurements in the free 4-Pillar Healthspan Assessment, run in our Manulife Tower studio in the CBD. For a standalone scan, expect roughly SGD 35 to 45. Wherever you go, scan on the same machine at the same time of day so the readings stay comparable.

Q. Who should not get a DEXA scan?

DEXA uses a very low radiation dose, but pregnant women should defer it, since any radiation is avoided in pregnancy as a precaution. If you have had a recent test using contrast dye or a nuclear-medicine scan, wait until it clears, as residual contrast can distort the read. Metal implants, pacemakers, or prosthetics within the scan field can skew regional results, so tell the radiographer beforehand. For routine body-composition tracking with none of these factors, an InBody scan sidesteps the question entirely, since it uses no radiation at all.

Q. Can I use Medisave for a DEXA scan?

It depends on why the scan is ordered. A bone-density DEXA requested as part of osteoporosis screening or a clinical diagnosis, particularly for post-menopausal women, is more likely to qualify for Medisave or subsidy than a body-composition DEXA you request yourself for fitness tracking, which is usually out of pocket. The rules sit with the clinic and your GP, so confirm before you book. If bone health is your concern, the menopause and bone-strength programme covers how strength training protects bone mineral density alongside whatever screening you choose.

Citations

Antonio, J., Kenyon, M., Ellerbroek, A., Carson, C., Burgess, V., Tyler-Palmer, D., Mike, J., Roberts, J., Angeli, G., & Peacock, C. (2019). Comparison of Dual-Energy X-ray Absorptiometry (DXA) Versus a Multi-Frequency Bioelectrical Impedance (InBody 770) Device for Body Composition Assessment after a 4-Week Hypoenergetic Diet. Journal of Functional Morphology and Kinesiology, 4(2), 23. pmc.ncbi.nlm.nih.gov/articles/PMC7739224

McLester, C. N., Nickerson, B. S., Kliszczewicz, B. M., & McLester, J. R. (2020). Reliability and Agreement of Various InBody Body Composition Analyzers as Compared to Dual-Energy X-Ray Absorptiometry in Healthy Men and Women. Journal of Clinical Densitometry, 23(3), 443-450. sciencedirect.com

Chen, L. K., Woo, J., Assantachai, P., Auyeung, T. W., Chou, M. Y., Iijima, K., Jang, H. C., Kang, L., Kim, M., Kim, S., Kojima, T., Kuzuya, M., Lee, J. S. W., Lee, S. Y., Lee, W. J., Lee, Y., Liang, C. K., Lim, J. Y., Lim, W. S., Peng, L. N., Sugimoto, K., Tanaka, T., Won, C. W., Yamada, M., Zhang, T., Akishita, M., & Arai, H. (2020). Asian Working Group for Sarcopenia: 2019 Consensus Update on Sarcopenia Diagnosis and Treatment. Journal of the American Medical Directors Association, 21(3), 300-307.e2. jamda.com

Pang, B. W. J., Wee, S. L., Lau, L. K., Jabbar, K. A., Seah, W. T., Ng, D. H. M., Ling Tan, Q. L., Chen, K. K., Jagadish, M. U., & Ng, T. P. (2021). Prevalence and Associated Factors of Sarcopenia in Singaporean Adults: The Yishun Study. Journal of the American Medical Directors Association, 22(4), 885.e1-885.e10. jamda.com

Vendrami, C., Gatineau, G., Gonzalez Rodriguez, E., Lamy, O., Hans, D., & Shevroja, E. (2024). Standardization of body composition parameters between GE Lunar iDXA and Hologic Horizon A and their clinical impact. JBMR Plus, 8(9), ziae088. pmc.ncbi.nlm.nih.gov/articles/PMC11299512

Boykin, J. R., Tinsley, G. M., Harrison, C. M., Prather, J., Zaragoza, J., Tinnin, M., Smith, S., Wilson, C., & Taylor, L. W. (2021). Offseason Body Composition Changes Detected by Dual-Energy X-ray Absorptiometry versus Multifrequency Bioelectrical Impedance Analysis in Collegiate American Football Athletes. Sports, 9(8), 112. pmc.ncbi.nlm.nih.gov/articles/PMC8402408