InBody Scan Sydney: What Body Composition Really Tells You

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 honest version, 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.

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.

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