Why is the Styku body fat % different from other devices?

Every method, whether it’s caliper, Styku, BIA, DEXA or dunk tank will give a range of body fat % values, some higher, some lower, and there’s no “ground truth” when it comes to an accurate body fat %. It’s the key to moving forward with tracking progress and the body’s change. A sample caliper value may be 13%, DEXA 18%, BIA at 25% and Styku at 23%. It’s truly that variable because of the difference in the methods used and the limitations of each of those methods.

For example, BIA body fat calculations are derived from the water content of the body. Change the hydration level, and the body fat % values will change as well. DEXA is quite precise as a body fat % system, but it does take 5 minutes to perform a DEXA scan and any movement during that time will skew the results. Operators at the dunk tank will take measurements 3 times and use the average, because the air in a person’s lungs when “dunked” has a big impact on the resulting body fat % calculation.

The Styku method of estimating body fat uses circumference measurements to derive the result, so any issue with the scan (ie., arm issue) may impact the result (for instance, a common issue is when women don’t tie their hair up into a bun, because we use the neck measurement to calculate body fat % for women). 

Also, the dataset used to derive the algorithm for body fat % was made up of an “average” range of body types, and some subjects may have an atypical body. Off-the shelf circumference methods, for example the YMCA or US-Navy method, will likely over-estimate their body fat % as well due to the body type being uncommon in the population.

I would also reiterate that regardless of the body fat % result, whether it’s a bit higher or lower than another method, when the Styku scan is performed correctly the results are quite precise, meaning you will see very little change in the value for several scans performed one right after the other. This is key because without good precision, it’s very difficult to track progress.

For example, calipers have a precision of about +- 5%. The subject’s trainer may have calculated the body fat % at 13%, but if we had the trainer calculate the body fat % several times, we would see that sometimes it’s 15%, sometimes it’s 12%, etc. In order to truly know that progress was made in lowering body fat %, with calipers we’d need to see a change greater than 5%.

With Styku, the change will be accurately recorded for 2% or more, so if the customer is interested in knowing whether they gained or lost fat, Styku will be able to deliver more quickly than calipers.

Breast implants will not affect the Styku body fat % calculation because we don’t use the chest measurement to calculate body fat % for women. It could certainly impact another method of calculating body fat, though, and the results may be different in one of the other systems than in Styku’s, certainly. For example, the Jackson-Pollock method for determining body fat % via calipers uses a chest skinfold that could definitely be impacted by implants. The resulting caliper-based body fat % value would be different as a result.