Body fat scans: what are your options?

We checked out DXA Scan, Evolt 360 Scanner and Fit3D.

Midsection of female healthcare worker analyzing x-ray image on computer monitor. Senior male patient is lying on examination table.

Our test of body fat scales found they aren’t hugely accurate and don’t give the full picture about where you’re storing your fat – essential for knowing your risk for diseases such as heart disease and stroke. So, are there other alternatives? We checked out three options.

DXA Scan

Colour scan detailing fat, leanness and bone mass.

DXA (Dual-Energy X-ray Absorptiometry) scans, use a type of X-ray technology. These scans are regarded as accurate for measuring body composition and provide data on weight, body fat, muscle mass and bone density.

We paid $150 for a one-off appointment that took less than 30 minutes, which included a run-through of the results afterwards with a DXA technician. It’s a non-invasive test and you’re fully clothed (although you have to change into hospital scrubs).

Lying down, the scanner moves over your body a few times, compiling a picture of your skeletal structure, muscle and body fat. Your report breaks down your body composition results, including a colour-coded visual, and a summary of what the figures mean in terms of your age, gender and ethnicity.

As well as body fat composition, the scan also gives data about your bone mass density and indicates whether you’re at increased or high risk of breaking a bone – useful info to have if you’re at risk of osteoporosis or other bone diseases.

If you want to track your changes, you can have follow-up scans. Depending on the provider, this may cost less than your first scan.

Evolt 360

Using the same technology as the body fat scales we tested, the Evolt 360 claims to be “scientifically proven” and gives you results for 40 body composition measurements including body fat percentage, muscle mass and abdominal circumference. However, unlike some body fat scales in our test, it also breaks down where you’re storing fat.

Often located at fitness centres, it’s marketed as a tool to “quantify all your hard work”.

Three Consumer staffers headed to our local Les Mills gym to give the Evolt 360 a try. A single scan was $40 (cheaper for Les Mills members) and only takes a couple of minutes. Fully clothed, you stand on the machine squeezing two handles while it calculates your stats, including your “bio age”. Good news all round – all of us had a “bio age” younger than our actual age!

Woman holding hands on the dashboard modern technology device in beauty clinic.

As well as the printed report, you can access your information on an app and track your progress with additional scans.

The bad news was the accuracy. Compared with the DXA scan, the Evolt 360 was way off. Our male volunteer got a reading of 11.5 percent body fat, compared with 21 percent on the DXA. The two females got readings of 24 percent body fat, despite being more than 30 percent fat on the DXA scans. This machine may give you a false sense of security about your health.

Fit3D Body Composition Scanner

Claiming to be the most accurate mobile 3D body composition scanner in the world, we sent two volunteers to Health + Fitness Testing NZ (a male and female) for a scan.

The $100 scan only takes 40 seconds and is a similar process to the Evolt 360. The main difference is the platform rotates while an infrared camera takes images for the scan – one volunteer likened it to spinning like a car in a showroom display!

The 3D scan takes over 400 body composition measurements and you’ll also get a full posture report. You can access your information online or with an app so you can track progress with subsequent scans.

As far as body fat goes, the scan was fairly accurate for our male tester – a difference of only about one percent. For the female, the Fit3D wasn’t as accurate. Fit3D calculated her body fat percentage as 29.4 percent, compared with 37 percent on the DXA.

Expert advice

Professor Jeremy Krebs, endocrinologist at the University of Otago’s Department of Medicine said scanners like the Evolt 360 and Fit3D are only estimates and subject to errors. “Body fat is calculated from algorithms derived from studies comparing these scanners to a reference method. The algorithm is specific to that population and ethnicity, and not to an individual.”

Professor Krebs also cautions about any scanners claiming to calculate a biological age. “Don’t be fooled by the flash websites and smoke and mirrors,” he said.

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29 Nov 2020
DXA vs Aria Scales

I have the Aria Scales (not Aria 2), and have also had two DXA scans (about 18 months apart). On average the Aria reported a Body Fat percentage of 17%, at the time the DXA reported 19%.

The DXA results are split into muscle mass, bone density, and fat is split into visceral and other. They also calculate your basal metabolic rate.