How Tech Can Help Measure Your Body Fat Percentage

20 Minute Fitness Episode #69

On today’s 20 Minute Fitness episode we’ll dive right into a very useful and key indicator of your health & fitness, which is body fat percentage. After laying down the basis of what your body fat percentage is and why it is superior to, for instance, BMI, Charlie gets into how you can actually measure it. You’ll learn about all sorts of methods, from more basics with greater margin of error to very futuristic and much more accurate ones. So press play now!

Check Out Our ‘Ultimate Tracking Guide’ To Get A Comprehensive Guide On Measuring Your Fitness Progress

Three Things You Will Learn

1) The Simple Ways Of Measuring Your Body Fat Percentage

If you think that body fat percentage can only be calculated with super high-tech gadgets, you’re wrong. There is a method that is accessible to virtually anyone with a measuring tape and an online calculator. Simply head to a website with a calculator, such as active.com, plug in your body data and let the magic happen. Now of course the downside of this method is the element of human error.

Getting a bit more techy and stepping up on the ladder of accuracy, you can download Body Barista from the App Store. This app tracks your body composition and muscle groups through the phone’s camera using a patented technology. Listen to this week’s episode to learn how Body Barista works and achieves its ± 5% accuracy!

2) The Handheld Devices

There are several devices out in the market, which use more scientific techniques to calculate your body fat percentage. One of the most well-known ones is the Omron Handheld Body Fat Analyzer. This very compact and easy-to-use device uses Bioelectrical Impedance Analysis to give feedback on your body composition. While it has many advantages, like its portability and low cost, this device has also been criticized for its low accuracy.

Another gadget that is built on a similar concept is the Skulpt Scanner. The Skulpt Scanner was founded by a neurologist at Harvard Medical School, who originally aimed at building a solution to track the progress of his patients with muscle disorders. So he built a device that uses Electrical Impedance Myography, which later on proved to be an effective method for everyday people to track their health & fitness.

Press play and find out more about both Omron & Skulpt and which one has been found to be more effective according to users!

3) The Future Of Tracking Your Body Fat Percentage

Lastly we arrived to a device that’s more technical, quite futuristic and definitely has greater accuracy. ShapeScale is a first-of-its-kind 3D scanning body scale that tracks and visualizes the user’s body composition. ShapeScale uses volume and weight measurements to calculate not only your overall, but also your localized body fat percentages.

Besides the detailed and accurate feedback, you also get access to your interactive and photorealistic  3D avatar and various cool features. These include the Heat Map, which uses color coding to show where you’ve been losing fat and/or gaining muscles, and a lot more…

Tune in to hear all about the technology behind ShapeScale and what other features this magical device has to offer!


Profound Performance have been formulating and producing innovative and cutting-edge nutrients, supplements and health products since 2001. Regardless of your chosen sport, exercise or training, their unique supplements allow your body to work to its optimum performance.

Visit www.profound-performance.com to order your supplements today and start living a healthier life tomorrow

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Full Transcript

00:04: Hello, and welcome back to another episode of 20 Minute Fitness. Once again, to our regular listeners, thank you very much for stopping by. I really hope you’re enjoying the podcast still, and just to let you know, we really do appreciate all the support. And a special welcome to anyone that is new or stopping by for the first time today. So really, hope you enjoy, and if you do, do not forget to subscribe on whichever podcast player you listen to your podcasts on. Don’t forget, we do love hearing from you, so don’t be afraid to reach out and give us suggestions for future episodes. If you think there’s anyone we should interview for the other series, if you think there’s any tech we should cover with regards to the fitness industry, then we’d also love to hear from you, or if you’ve had any experience with any of the technology we’ve already mentioned before.

00:44: But today we’re looking at a favorite topic of mine, which is how technology can help measure your body fat. But of course, before we dive in, this podcast is powered by ShapeScale. ShapeScale is a 3D body scanning scale where you simply step onto the device, it will calculate all kinds of incredible body data, such as your body fat percentage and your lean muscle mass, and also give you a photo realistic 3D avatar of your body so you can see the changes that occur over a period of time. It’s now available for pre-order at shapescale.com.


01:16: We know how important it is to look at your body composition to see how far you’ve come since you’ve started your fitness journey, whether that be you’ve started eating better, a more balanced diet, or you’ve started working out more regularly. Or if you’re looking to gain muscle mass, just having an idea of how your body composition has progressed will really help you understand whether the tweaks you’re making to your training are working or not. And obviously, in this episode, we’re looking in particular at body fat. Obviously, most people in most circumstances would like to reduce their body fat, so tracking your body fat as it starts to decrease can be great for your motivation to see that number go down, and obviously it keeps you accountable. It makes you want to better that number each week, week in, week out.

01:53: We do have a really informative long blog post on the world of tracking as well, which does cover tracking your body composition, so if you want to check that out, you can check it out on the ShapeScale blog, and that is the ultimate tracking guide which now has over 15,000 views. So it’s doing really well and hopefully providing a lot of value to people out there. Traditionally, when we thought about whether someone is healthy with regards to their body composition, we’ve thought about metrics like BMI, but to be honest, it’s not accurate enough. In the formula for BMI, weight is used, but it doesn’t distinguish between your fat or fat-free mass. So it’s not really accounting for someone that has a lot of muscle, and obviously we know that the more lean muscle you have, the more it helps to burn fat. So, for example, if you’ve got a lot of muscle or a large frame, then even though you might appear to be healthy, you’ll score highly on the BMI, which might even show you to be overweight or obese, so this is why we prefer to look at body fat percentage.

02:45: BMI doesn’t directly measure fat and it can miscategorize people as healthy who have a normal weight for their height, when they’re actually carrying too much fatty tissue, for example. Whilst body fat percentage literally measures the percentage of your body made up of fat, and everything else is usually referred to as lean tissue. So this gives a more accurate representation of a healthy, fit, lean individual that’s working out hard, physically active, and obviously watching what they eat. Recently as well, I read a study in Science Daily that’s been published in scientific reports and one of the nature journals and they’ve been looking at different formulas we can use to actually look at body composition. So Orison Woolcott, who is the head of the study, said he wants to identify a more reliable, simple, and inexpensive method to assess body fat percentage without using sophisticated equipment, and so they came up with the relative fat mass index, or the RFM, and it only uses height and waist circumference measurements.

03:35: And they researched and examined more than 300 possible formulas for estimating body fat using a large database of 12,000 adults who recently participated in a health and nutrition survey, and they actually found that their results from the new formula, the RFM, were a better measure of body fatness than many indices that are currently used in medicine, including the BMI. And they compared 3,500 patients’ body fat percentages using the RFM formula to what they got using a DEXA scan, which is obviously the gold standard of body fat percentage calculations, and we’ll get on to that later, and they found out the patients’ RFM results corresponded most closely with the precision of the DEXA body scan.

04:12: So there are constantly new ways trying to be thought of how to measure our body composition. As we know, it is so important for our motivation to buy in to where we want to be in the future and also to see where we’ve come from, and how well we’ve progressed. Not much new tech has actually come out in this space in the past few years so some of these you may already be aware of, but some of them are still very exciting and it’s a very interesting subject, I think. So, we’ll now move on to the tech that helps to measure our body fat percentage. We’ll start at the most accessible category. So we will look at first a sort of a hybrid, it’s a mixture of technology and a physical, tangible object. It’s a tape measure. So at a very basic level, if you have a tape measure handy, there are a number of online calculators, such as the one on Active.com, and they allow you to plug in your body data that you calculated when measuring yourself with the tape measure and with the scale, and this presents you with your body fat percentage.

05:02: So for example, for a female, they’ll require you to input your weight in pounds, your waist circumference, your wrist and hip and forearm circumferences as well, and then you’ll be presented with your body fat percentage. Of course, using a method like this is very difficult to maintain accuracy because you quite often don’t measure yourself at the same anatomical point each time so that can lead to inaccuracy. However, if you are constantly using the same bit of apparatus you should be able to determine whether your body fat is going down or going up or plateauing, because even if the method of measuring your body fat percentage has a margin of error plus or minus 5%, but you keep using it, you keep using the same bit of apparatus and if you do the test at the same time of the day, with the same factors controlled as in what you’ve eaten and drunk for the day, as long as you see the number decreasing, then your body fat percentage should be decreasing as well.

05:49: Next up we’re going to look at an app I’ve recently come across and it’s called BodyBarista. This app reportedly tracks your body composition through your phone’s camera. So the app states that they can get the measurements of all of your body parts and muscle groups from pictures alone through a patented technology that extracts and tracks your physique in fractions of inches and centimeters. And it also claims to recently be able to measure your body fat percentage in a beta version of the app they’ve just released. So BodyBarista claims its body fat percentage function has an accuracy level lying between a bioimpedance scale, which we’ll get on to in a bit as well, and if an expert conducted a skin fold test on the subject as well. So this is in 2018 in September, they claimed that their accuracy is 0.6 lower than skinfold measurements, if we consider this using statistical regression methods. So the BodyBarista, when looking at body fat percentage is at the moment, accurate to plus or minus 5%, being slightly under the skin fold test conducted by an expert and above a bioimpedance scale.

06:48: So, how does it work? It’s quite complicated to explain and also looks quite complicated to actually conduct. So, you take a picture of you in the app, and it tells you how to stand in the app as well. You have to stand in a certain way for the algorithm obviously to be able to calculate your body fat percentage, and you have to validate the points in the picture, which means you pin the points to your body parts and that will be made more clear within the app. It’s quite difficult to explain without it in front of you. And then you’ll be presented with your data in graphs and pictures over time so you’ll be able to see that progress and hopefully stay motivated as you see it moving in the right direction.

07:18: I have seen there are fairly positive reviews in the app store, but as I said, it is a fairly new app, it’ll be very exciting to see the developments. And it has released a few new features as well, so the app allows you to compare progression photos, which is great for your accountability, but obviously, you can just do this within the iPhone photos app, for example. So, BodyBarista is free to download, and in order to take your measurements whilst at home or at a different location, you can pay per time using it or per three months. So, for two times you’d be looking at $4.99 cents, or for a three-month subscription, it’s $8 per month in that three-month period.

07:52: There are a few other apps that allow you to calculate your body fat percentage. For example, the Body Tracker Body Fat Calculator, but again this uses technology that already pre-exists. So for example, they’ll show you where to do your skin calliper fold test, how to pinch the skin for example, or where to do your tape measure measurements, and then you’ll input the data into the phone and you’ll be presented with your body fat percentage. So there’s that option as well if you didn’t want to log online and use a calculator each time, you could store it within an app.

08:20: If we move on to the mid-level category, we’re going to look at the Omron handheld. So, the Omron Handheld Body Fat Analyzer is a small device that you grip with both hands and it has the digital screen display in the middle which depicts your body composition data. So it calculates your data through a method called bioelectrical impedance analysis, and it is scientifically described as the ability of biological tissue to impede electrical current. So what does this mean and how does it work? So, what happens is, through the hand grips, a weak current passes through your body and different types of tissue and substances in the body will respond differently to that low voltage current going through the body. The fat tissue didn’t conduct very well whilst fat free mass, which includes your water, your muscle, and your bone conducts far better, and this is predominantly due to the amount of water in your muscles and the amounts of electrolytes dissolved in your body’s water that makes it conductive.

09:14: So the sensors in the Omron, they measure the impedance, which is the returning voltage to the sensors after its traveled through your body’s fat and fat free mass. The device then enters your body’s response into an equation and it will present you with the results. So it has a number of benefits, obviously, having this. It’s very convenient and very fast, very portable, you can use it wherever you want. It costs anything from around $60 to $100. There’s no discomfort or anything like that. Potentially, you might have discomfort doing a hydrostatic weighing test, and it can to some extent, differentiate between muscle and fat, so it’s already superior to a traditional scale.

09:48: However, there are inaccuracies associated with the bioimpedance scanners. So the electrical current usually follows the path of least resistance. So if you carry a large amount of fat underneath your skin, the bioimpedance analysis won’t even hit it, instead passing through internal tissues. And according to Science for Sport, eating and strenuous exercise two to four hours prior to the assessment has also previously been shown to decrease impedance, which ultimately obviously affects the accuracy of the measurement. So, it’s a step in the right direction definitely, but not without its limitations. At this stage of the episode, we’d like to say a massive thank you to our sponsor.


10:26: This episode of 20 Minute Fitness is brought to you by Profound Performance, tomorrow’s supplements today. Profound Performance have been formulating and producing innovative and cutting edge nutrients, supplements, and health products since 2001. Regardless of your chosen sport, exercise, or training their unique supplements allow your body to work to its optimum performance. Even though I work out four to five times a week, I had actually not been using supplements before, but I got a chance to try out the Profound Performance products and have been using them for a couple weeks now, and can really feel the difference. It’s like getting an extra energy boost and being able to push harder during every single workout, which is an absolutely amazing feeling.

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11:41: And now, back to the show. And let’s look at Skulpt. So, Skulpt was founded by Dr. Seward Rutkove, and he is a neurologist at Harvard Medical School. As a physician and a researcher he was really frustrated that there was no real good way to measure the muscle health of his patients, so he embarked on a mission to find and develop a better way to measure muscles. And in 2009 Dr. Rutkove and his co-founder, founded Skulpt to develop EIM devices to track the progression of patients with muscular disorders. We’ll touch on EIM in a little bit, but it stands for electrical impedance myography. After the initial thoughts of how Skulpt could help to track the progression of patients with muscle disorders, the team soon realized that EIM could be really helpful for people trying to maintain and improve and track their fitness, and in general trying to be healthier. And their studies have shown that stronger, leaner muscle has higher muscle quality so they’re able to quantify that and help you track that progress of whether they are increasing their muscle mass.

12:38: But Skulpt also lets you analyze your body fat percentage as well. So Skulpt is a small handheld device, smaller than the Omron, that can be used to calculate both overall and localized body fat percentage. That’s where you can see the body fat percentage on the different particular points in your body, for example the right arm versus the left arm, or the right bit of your chest to the left chest. And as mentioned, it does also track your muscle quality, and that’s of 24 different muscle groups. And the information it collects from the scanner is then synced to the Skulpt app. So when you’re using Skulpt, you need to ensure that you wet the electrodes, there’s a number of electrodes on the other side of the handheld device, and you position the Skulpt on the body parts as demonstrated in the app, and it’ll guide you through. They’re usually glowing green once you’ve obviously positioned the device in the right place. And what I was saying earlier about muscle quality is it’s a rating of your muscle’s fitness. So a high muscle quality score usually mean you have a lean, strong, fit, and healthy muscle.

13:35: So, I mentioned it worked by a process called electrical impedance myography. And obviously, that sounds a little bit like the bioelectrical impedance analysis that’s used by the Omron. So similarly to that process, it passes a small electrical current through the specific muscle group to assess an estimation of total body fat percentage and, obviously, muscle quality. Reviews of the Skulpt have been very mixed. One of the blogs I was reading when trying to find out people’s verdicts of Skulpt was the Very Well Fit blog, and the editor was quite quick to criticize and declare that they tested the same site on their body in quick succession three times, and the results fluctuated by up to 10%, which is obviously not at all ideal because it’s not even maintaining consistency for you to use it as a base measure. And obviously, to fluctuate by 10%, plus or minus 10% body fat is quite significant as well, so not ideal.

14:24: However, I also came across a study that was called investigation of the accuracy and reliability of body composition assessed with a handheld electrical impedance myography device. And the purpose of this study was to compare the body fat percentage assessed with a unique handheld EIM device, along with other methods such as the DEXA scans, skin fold tests, and also the bioelectrical impedance analysis. And once testing, they actually found the total error… They tested over 72 hours I believe, and the total error for both days was largest for the skin fold test and the lowest was for the EIM measurements. So obviously, that’s quite supportive of its relevance to measuring body fat percentage and body composition. The investigation, they actually found supported the use of a handheld EIM device as an accurate, a reliable method of estimating body fat percentage. So potentially there is some scope in the electrical impedance myography world and we’ll see if that progresses as time goes on as well.

15:19: However, obviously, there are a number of benefits for Skulpt as well. It is very portable, it’s very small. You do have to wet it, but apart from that you can do it almost anywhere. More often than not, it does give you a reasonably accurate body fat reading and you can sync multiple users and multiple devices to a single Skulpt app so you can obviously just flip between the different user profiles to track multiple friends or family on the one device. And at a fairly reasonable price, the Skulpt will set you back around $100. So, we’re very interested in hearing if anyone’s previously used the Skulpt. I have myself and never had too many difficulties with the accuracy of the device and I did find it quite easy and quick to get the hand of. Occasionally, you do have issues trying to locate the exact site until it obviously picks up the reading, but apart from that, I did find the process relatively convenient.

16:05: Moving on to the high end category now, and we’re gonna look at 3D body scanners, in particular ShapeScale. So as you will know from the intro, ShapeScale is a 3D body scanning scale. So you’ll step onto the device, a robotic arm will rotate around your body up and down, and the sensor head will tilt up and to the back to be able to capture the rest of your body, and it’ll capture body data and sync it to your phone. You’ll then be able to see metrics such as your body fat percentage, your lean muscle mass, and your muscle girths, as well as a visual representation of your body in photorealistic 3D. Before we get on to how ShapeScale works and how it calculates your body fat percentage, I thought I’d run through very quickly some of the cool features. So beyond the metrics that you can measure, you’ll also have the opportunity to see where you’ve been gaining muscle and losing fat as heat maps will be overlaid onto your body’s avatar to show you the areas which have been changing.

16:54: So you’ll be able to see, if it’s glowing orange for example, where you’ve been building muscle and it might go blue from where you’ve lost fat as well, so that’s really useful and obviously, it’s just another way of you getting an extra sense of motivation that there are changes happening to your body according to the differences you’ve made in your daily routine. You can also have a look at something called the Difference View, where you’ll be able to see detailed changes over different time periods that have occurred to your body over a certain period of time as I said, but depending on your workout routine and diet, you will see visual changes over time, and it will show it in a nice little GIF or almost graphic video. So that’s again, another way for you to fully understand the small changes that are occurring to your body.

17:32: So how does it all work? What’s going on when the robotic arm spins around your body? It’s all very futuristic. Well, ShapeScale uses depth sensing and software algorithms, so it has an RGB and depth sensor which will rotate around your body to capture the data. And the depth sensor projects infrared coated light onto your body to catch the depth of close to 50 million points every second. This point cloud is then converted into a very accurate body model, and the RGB camera captures dozens of photos that are then sliced and stitched together to create a photorealistic texture. This information is then sent back to the servers at ShapeScale that will compute your photorealistic 3D avatar and this will enable you to track changes in your body down to the slightest detail because it’s not just a gray shell of the body, it’s actually all in color and you’ll be able to work out what’s going on where.

18:17: As mentioned in the intro, ShapeScale is available for pre-order at ShapeScale.com and I think it’d be really, really exciting for when it’s shipping. There are a number of other devices as well that could technically be fit into the premium or high-end category, that being the gold standard DEXA scan which uses a three-compartment model, so it divides your body into bone mineral, fat mass, and fat-free mass. And it basically passes a low radiation x-ray beam through your tissues with varying energy absorption, allowing the practitioner to determine the tissue type and quantity, so you can work out your body fat percentage that way, and it is the gold standard. It’s what most different methods of body fat percentage calculations are compared to. And this will set you back anywhere from $50 to $150 per test, so potentially, you won’t be able to use it all of the time obviously because it will become quite a costly affair.

19:07: And I’m sure a lot of you are familiar with a number of these different premium ways of measuring your body fat percentage such as hydrostatic weighing, you can also use an InBody, which uses bioimpedance analysis but a very expensive model which will remove some of the limitations that the normal bioimpedance scales have. There’s also the Bodpods, which calculates your body fat by displacing air when you get inside as opposed to the hydrostatic weighing, which is obviously displacing water. But as I said, I’m sure a number of you are already familiar with these different techniques so we won’t run through them. But I really do hope you’ve learned something about the different technology out there currently that can be used to measure your body fat percentage. It’s very interesting for me to see the new apps come out to be able to do that, and it’s interesting to see different formulas that are also coming out that can help us go beyond the BMI, which is so flawed as well.

19:53: If you know of any other devices that are coming to market or are already currently out as to how we can calculate our body fat percentage… Obviously, we know there’s different methods, like the skin caliper test and everything like that, but we wanted to think about what technology is out there currently that helps us do this. So, do get in touch if you know of any other methods we can do this. It’s a very interesting subject and I think it’s very interesting to see the different limitations and advantages of each. So that’s all for this week and we will catch you next time.


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Lilla Laczo

Lilla is a content writer and community manager at Shape.
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