Body Composition
InBody Scan Sydney: What Body Composition Really Tells You
By Brad Ellison · · Updated 16 September 2026

An InBody scan uses a 60-second bioelectrical impedance test to estimate how much of your body is muscle, fat and water, the things a bathroom scale cannot separate. It is most useful for tracking whether you are losing fat and holding onto muscle over time, rather than for a single official body-fat number. This guide explains what each metric means, how accurate the scan actually is, and how to prepare so your results are worth trusting.
Why the scale misleads you
Your bathroom scale measures one thing: total mass. It cannot tell the difference between a kilogram of muscle, a kilogram of fat, or a litre of water you are holding after a salty dinner. Two people at the same weight can have completely different health and shape, and the most encouraging early sign of good training, losing fat while gaining muscle, often leaves the scale unchanged for weeks.
Body composition analysis splits that single number into its parts. Once you can see fat, muscle and water separately, the scale not moving stops being discouraging and starts being information.
What an InBody 570 actually measures
The InBody 570 sends a safe, low-level electrical current through your body and measures the resistance it meets, because fat, muscle and water each conduct differently. The metrics worth understanding:
- Skeletal Muscle Mass (SMM): the muscle you can build through training. Watching it rise over months is the clearest proof your program is working.
- Percent Body Fat (PBF): fat as a share of total weight, more meaningful than BMI, which cannot tell a muscular person from an overweight one.
- Visceral fat level: fat stored around your organs, the number most tied to long-term health. It can fall even when weight holds steady.
- Basal Metabolic Rate (BMR): roughly how many calories you burn at rest, a sensible starting point for nutrition.
- Segmental lean analysis: muscle broken down by each limb and your trunk, which flags left-right imbalances worth correcting before they cause injury.
- Body water (intra- vs extracellular): useful for spotting inflammation or poor recovery behind a sudden weight jump.
How accurate is it, and is DEXA better?
Here is the full picture, because it matters for how you use your results. Independent studies show the InBody 570 correlates strongly with DEXA, the research gold standard, at around r = 0.94 to 0.98 for body fat and muscle. But the same studies find a systematic bias: InBody reads body fat and muscle slightly differently from DEXA on any single reading.
The practical translation: InBody is very good at measuring change and less reliable as a one-off official body-fat percentage. If your first scan says 24% and DEXA would say 26%, that gap barely matters. What matters is that the same machine, in the same conditions, shows you dropping over the following months. For tracking a transformation, that consistency is exactly what you want, without DEXA radiation, referral or a clinic visit.
So if you need clinical bone-density data, DEXA is the right tool. For tracking fat loss and muscle gain every few weeks, the InBody is the more practical choice, provided you keep the conditions consistent.
Tracking body composition on a weight-loss medication
More Eastern Suburbs members are now losing weight on medications like Ozempic, Wegovy and Mounjaro, and the scan matters more than ever, because these drugs can strip muscle along with fat. A set of scales cannot tell the difference. An InBody can. We take a baseline before or early in treatment and re-scan every four to six weeks, so if lean mass starts to slip we can adjust training and protein before it costs you. If that is you, read our full guide on how to lose fat, not muscle, on weight-loss injections.
How to prepare for an accurate scan
Because the reading depends on your body water, small things shift it. To keep scans comparable:
- Same time of day, ideally morning, before heavy food, caffeine or training.
- Hydrate normally the day before; do not over- or under-drink to game the result.
- Fast 3 to 4 hours beforehand so stomach contents are not counted as tissue.
- Skip training, caffeine and alcohol in the hours before, as they change blood flow and water balance.
- Remove shoes, socks and heavy metal; the scan needs clean skin contact at eight points.
One kilogram of gain on a scan taken after a workout and a coffee is usually water, not muscle. Consistency is the whole game.
Turning the numbers into a plan
A scan is only useful if it changes what you do next. At 6X we scan at the start and then every 4 to 6 weeks, and we use the results to adjust rather than just record:
- If SMM is flat while you are dieting, we protect muscle by raising protein and prioritising resistance work.
- If visceral fat is high, that becomes the primary target, ahead of the scale number.
- If segmental analysis shows an imbalance, we adjust your program to even it out.
What a healthy result actually looks like
Two questions come up in almost every scan review: what body fat percentage should I be at, and what counts as normal. The useful answer is that the healthy range is wide, it shifts with sex and age, and chasing one figure distracts you from the trend. Waist circumference is far less vague. Australian guidance puts increased health risk at 94cm or more for men and 80cm or more for women, and substantially increased risk at 102cm and 88cm (Better Health Channel). We run a tape measure alongside the scan for that reason: two cheap markers moving the same way is stronger evidence than either one alone.
If percent body fat is falling, skeletal muscle mass is holding or rising, visceral fat is dropping and your waist is coming down, the program is working. That stays true whether the scale moved much or not.
Where to get an InBody scan near Maroubra
We run an InBody 570 at 319 Malabar Road, Maroubra, and scans are open to anyone across the Eastern Suburbs, including Malabar, South Coogee, Coogee, Randwick, Kingsford, Matraville and Pagewood. You do not need to be a member. Coaches are on the floor Monday to Friday 5:30am to 8:30pm and Saturday 7am to 12pm. The measurement itself takes about 60 seconds, so allow a little longer on a first visit and a coach will walk you through the printout until you know which two numbers to act on. If you are still deciding where to train, our guide to choosing a gym in Maroubra covers what a facility should be measuring and why access on its own rarely changes anything.
Ready to see what you are actually made of? Book an InBody 570 scan at our Maroubra studio and a coach will walk you through every number and what to do about it.
Questions
Frequently asked questions
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- Weight-Loss Injections and Muscle: How to Lose Fat, Not Strength
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- Menopause and Weight Gain: What Actually Works After 45
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This article is general information for healthy adults and is not medical, dietetic or physiotherapy advice. Speak with your GP or a qualified health professional before starting a new exercise, nutrition or recovery program, particularly if you have an existing injury or medical condition.
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An InBody scan separates fat from muscle so your training and nutrition are set from data, not guesswork.