In this video, I talk about the various methods you can use to track body fat for fat loss and how often you should be testing your body composition.

Body Composition Testing Methods

In the previous AFL posts, I went into detail with why body composition testing is better than tracking your body weight and expanded on that with 5 reasons you should track your body composition. Continuing the trend I wanted to take this opportunity to look into the various methods you can use to test your body composition and help you determine which one would be best suited to your needs and budget.

No.1 Skinfold Calipers

Skinfold caliper testing is the only method discussed in this post that actually has a large degree of human interaction – it’s quite an intimate experience with someone who is quite likely to be a stranger to you.

When someone measures your skinfolds they quite literally have to pinch your excess skin and pull it away from your muscles then use special calipers to take those measurements – quite invasive if I may say.

Before breaking down skinfolds, I want to take this opportunity to share a story. Back when I was relatively new to training, the gym I worked at had us do skinfold caliper testing for our clients. Not only that, but our first session was always designed for goal setting, testing body composition, and mobility screening. Now, for men, when you do a 3-site or 7-site test they typically have to take their shirt off so you can take their appropriate skinfolds.

Enter my new client, a man who I had known for the sum total of 5 minutes – of which we had spent on a bodyweight scale and measuring his blood pressure. The next step of our assessment was to test body composition. So respectfully I asked him to take his shirt off and in response to my request he told me, “Why don’t you buy me dinner first”.

To this day, his response still cracks me up.

PS I didn’t buy him dinner, just pinched him a few times instead.

Back to testing… The 3 common methods to do skinfold testing 3-site, 4-site, and 7-site. The only important note here is that the more sites you test, the more accurate the test becomes.

While skinfolds don’t take all that long to perform there are a few drawbacks that make this my least favorite method for testing body composition.

There is a large proponent of human interaction which also means there is a large potential for human error, especially with inexperienced trainers.
It’s quite an invasive/intimate experience to have with someone you might not know well.
Trainers could skew your results to make it seem like you are reaching your goal. Now while this is entirely possible, I’m going to give most trainers the benefit of the doubt and say it’s quite unlikely. That being said, it’s still possible.

Finally, before wrapping up, a standard skinfold assessment will set you back anywhere between $15-30.

In conclusion, while this method is not the most accurate it’s relatively quick to complete and it’s ultimately better than not knowing your body composition at all.

No. 2 Bioelectrical Impedance Analysis (BIA)

BIA scales are one of the most accessible ways you can measure your body composition and rid yourself of human error.

This type of test works by sending a current through your body – don’t worry, you won’t feel anything at all – and measures the resistivity of said current to determine your body composition.

NOTE This method works because current flows slower through fat and quicker through muscle.

There are 3 different BIA monitors you can be tested on or purchase for yourself.

Handheld BIA Monitors
BIA Scales
Segmental BIA Scales – these are typically used in large athletic facilities or clinics, as such it’s highly unlikely you’ll ever have one for personal use.

A standard BIA test will run you about $15-30.

PS One of my favorite things about BIA monitors/scales is that you become capable of knowing your body composition without needing to leave the comfort of your home, granted you have your own scale.

NOTE In my experience, the handheld monitors tend to be the least accurate.

Since BIA scales are available to the general public for purchase there happen to be quite a few out there. As for their accuracy, I can’t tell you for certain, it really depends on a scale-by-scale basis. The scale I have, from Amazon, is decent – it only set me back about $50, so it definitely didn’t break the bank. However, when comparing my scale to a $3000 Tanita scale I’ve found it to miscalculate my body fat by about 2%.

To be more specific, when I compared the two, my body fat on the Amazon (EatSmart) scale was 10% but on the Tanita, it was actually 12%. Now mind you, being “2%” lower in body fat sounds nice in concept, however, I like accuracy more than being at a lower body fat percentage.

PS I also wouldn’t spend an additional $2950 to be more accurate when it comes to a personal BIA scale.

That being said, because of the inaccuracy, I have from my personal scale, I have this Ironman Tanita ($150) hanging out on my wishlist itching to be purchased – plus it’s much nicer on my wallet too ;).

My good friend says she really loves hers and once I get a chance I’ll try to do a comparison of the EatSmart, Ironman Tanita, and the $3000 Tanita scale.

Of the methods discussed today, this is the second least accurate. Essentially, it’s more accurate than skinfold calipers but it definitely isn’t the Gold Standard of body compositional analysis (especially when you consider there are so many different models available for purchase).

All that being said, knowing your body composition via BIA is still better than the human error story that is skinfold calipers or not knowing at all.

In conclusion, BIA scales are great due to their increased accessibility and ability to purchase for home use. That being said they are still shy of the Gold Standard of body compositional analysis. So if you are looking for more accuracy… keep on reading.

No. 3 Hydrostatic Weighing

Hydrostatic weighing, for quite a long time, was the Gold Standard of body compositional analysis.

The premise behind the accuracy of this method is Archimedes’ Principle of Displacement or in Layman’s terms your buoyancy in water.

Since lean tissue has a higher density than water it tends to sink and since fat tissue is less dense than water it tends to float. So, if you’ve ever heard “muscle sinks and fat floats”, that’s why.

When getting hydrostatically weighed you are first weighed on dry land and subsequently in a large water tank on a special seated scale. This process is typically repeated 3 times and your body composition is determined using the averages of your dry weight and water weight.

NOTE If you don’t like being in a swimsuit and being dunked underwater than this method probably won’t sit well with you, but don’t worry there are 2 more to go.

Finally, hydrostatic weighing will set you back about $30-45, and a decent amount of time and wetness.

PS Of the methods I discuss today, this is the second most accurate, and it’s relatively affordable. So in exchange for saving money and a little bit of accuracy – relative to No. 5, you have to get wet and spend a bit more time being weighed.

No. 4 Bod Pod

The Bod Pod was designed with the goal of usurping hydrostatic weighing as the gold standard of body compositional analysis… Ultimately, it wasn’t able to knock hydrostatic weighing of its mantle.

Silver lining, it’s still more accurate than BIA testing.

While it didn’t replace hydrostatic weighing as the gold standard, it does provide you with a viable option to accurately test your body composition without having to get wet, which is definitely a plus.

A Bod Pod works by using air displacement technology in a closed environment – a Bod Pod tank – to determine your body composition.

Bod Pod test will typically cost you about $45-70 and takes about 3 minutes to complete start to finish. All you really have to do is sit in the Bod Pod and breath normally, it is recommended that you wear more form-fitting clothing, but other than that it’s a fairly straightforward process.

PS My favorite thing about the Bod Pod is that it looks futuristic and reminds me of a hibernation chamber from Alien. Or since I also happen to be a nerd with imagination, a hibernation chamber for the Hyperbolic Time Chamber – if you’ve never watched Dragon Ball Z you won’t get this reference.

Finally, convenience wise I find Bod Pods to be superior to hydrostatic weighing.

However, if you want to save a bit of money and gain a bit more accuracy than you may want to look into hydrostatic weighing. Granted you are fine being dunked under water.

No. 5 DEXA Scans

DEXA Scanning or if you prefer acronyms spelled out… Dual-Energy X-ray Absorptiometry. If you can’t tell from me spelling it out, DEXA scans determine your body composition through advanced x-ray technology. What’s more, this method has successfully usurped hydrostatic weighing as the Gold Standard of body compositional analysis.

I personally think this method combines all aspects of a great body composition test. It’s super accurate, relatively quick, and it’s capable of doing segmentation analysis (your body fat can be determined in specific locations; e.g. legs, arms, stomach, etc.).

Additionally, DEXA scans are more accurate for athletes and the elderly. This means if you are at a very low body fat with a large amount of muscle its accuracy won’t let you down, conversely, if you happen to be elderly with decreased bone density it will also continue to be accurate.

If you can’t tell, I really like DEXA scans…

In fact, the only thing I don’t like about them is the price. A single DEXA scan will typically run you $100… ouch.

Most people won’t be able to justify spending $100 just to accurately know their body fat, but if you have the money to do so and an itch to know your body fat with the new gold standard of body compositional analysis, then, by all means, DEXA scanning should be your method of choice.

BONUS – Circumference Measurements

Finally, I want to introduce a very low-cost method to tracking your body composition.

Full disclosure, circumference measurements will not be able to determine your body fat percentage (I have heard of a calculation that uses circumference measurements to determine body fat, but I don’t know enough about it to accurately expand on this method).

The most important thing to note when it comes to circumference measurements is you want to compare to one person and one person only, yourself. Your previous measurements will give you an idea of the progress you are making and give you concrete quantitative measurements that your body is physically changing inch-by-inch (or cm-by-cm if you happen to be anywhere but the US).

The most common testing sites are waist, hips, and bust, however, you are more than welcome to measure your arms, thighs, etc…

Additionally, if you don’t happen to already have a measuring tape you can easily purchase one for about $4-15.

The one I use has an auto retract button so I can’t cheat and cinch the measurement down. Not only that, but I only cost me $7.

NOTE For those of you that suffer from TCS, also known as Tiny Calves Syndrome, I recommend you avoid measuring your calves.

These measurements are much more resistant to positive changes when it comes to growing your calves; unless you happen to do a godly amount of volume for your calves.

Therefore, I cannot, in good conscience, recommend circumference measurements for anyone with TCS.

Before moving on, I want to introduce another useful approximation when it comes to circumference measurements. Losing 1 in. on your waist correlates to about 5 pounds of fat loss. I know this approximation to be relatively accurate for men, however, I’m not entirely certain how accurate it for women.

Losing 1 in. on your waist correlates to about 5 pounds of fat loss. I know this approximation to be relatively accurate for men, however, I’m not entirely certain how accurate it is for women.

At the end of the day, it’s still an approximation and ultimately decreasing your waist measurement, regardless of how much exact fat you lose, is a positive thing.

How Often Should I Test My Body Fat?

Bringing this post full-circle I want to discuss frequency of testing your body composition.

For all of these methods, I recommend replicating the conditions in which you test.

For example, if you test first thing in the morning, after your morning bathroom and Facebook session then every time you test should be first thing in the morning after your bathroom session (Facebook optional).

Body Fat

Typically, I recommend once per month.

This generalization will apply to Skinfold Calipers, BIA, Hydrostatic Weighing, Bod Pod, and DEXA Scanning

Any more than that and the changes you will see in your body composition won’t be as drastic and you become more likely to observe normal changes in your day-to-day body composition (e.g. dehydration, bloating, etc.).

By testing once per month you are able to see that your program is working effectively, not only that but it will save you some of your hard-earned money. Imagine DEXA scanning on a weekly basis… that’s $400 down the drain!

NOTE If you own a BIA scale then I will adjust this frequency to once per week. Mainly because you’ve already invested in the scale and it doesn’t cost you any additional money to test. The only drawback to testing on a weekly basis is you are more likely to see natural fluctuations in your weight and body fat that you wouldn’t notice testing once per month.

Circumference Measurements

Just like body fat, I recommend once per month.

Unlike with personal BIA scales, I don’t believe measuring this more frequently will be of any benefit. Especially when you consider dehydration, bloating, and natural weight fluctuations.

Additionally, seeing a larger change after a month of not measuring will be more reassuring than seeing natural fluctuations.

Body Weight

If happen to have you read the Fat Loss vs Weight Loss post or saw the video then you would know how much I dislike body weight testing.

It’s inaccurate, it doesn’t tell you anything other than your physical weight at a given moment in time, it doesn’t define you, it’s far too easy to get lost in what you weigh, and I could easily continue on this soap box for another hour… but I digress.

So… For those of you that will not be shaken by the rationality of body composition testing…

Once per week… No more…

Again, NO More!

Other than being entirely irrelevant when it comes to progress measuring, your natural weight fluctuations are very noticeable. You could easily change 5 pounds in a single day (yes, that is well within the bounds of natural weight fluctuations).

So if you happen to weigh yourself multiple times throughout the day, then respectively, you are very likely to see your pounds fluctuate like a roller coaster.

Regardless, I can assure you, you are not getting fatter throughout the day. Your weight is just naturally fluctuating.

PS I remember a few year ago there was one day when I was super dehydrated and sick my weight fluctuated 15 pounds in a 24-hour period.

Now, this is definitely a drastic example, but I want to emphasize my point.

Weight is only a number, and quite a useless one when it comes to tracking your body composition.

Conclusion

Wrapping up this track your body fat for fat loss post I want to quickly recap what I discussed.

There are 5 different methods you can use to track your body fat for fat loss all of which have various pros and cons. Of the 5 I believe BIA to be the most accessible to the everyday person, hydrostatic weighing to be the most accurate and cost effective, and DEXA scanning to be the king of body composition testing, granted you have the wallet to support testing via DEXA.

Additionally, if you want a low-cost way to track changes in your body composition, but not body fat, circumference measurements are super useful and relatively easy to complete.

Finally, I talked about how often you should test your body composition and why increased frequency is not in your best interest if you want to see concrete positive changes for the various methods addressed today.

Next, the freebie that comes with this post is the Caloric Intake Calculator; this calculator was specifically created to help you with your fat loss goals. More specifically, this free calculator will calculate the caloric and macronutrient intakes you need to reach your fat loss goal and how long it will realistically take you to get there.

Finally, I want to thank you for taking the time to go through this AFL post. I wish you the best of luck with your fat loss endeavor and I hope you have the wherewithal to now accurately track your body composition and lose fat with ease.

This post marks the end of the first AFL series, in the next series, I will be going more in-depth with Fat Loss 101, an all-encompassing approach to losing fat and how to set yourself up for fat loss success.

In the meantime, go confidently track your body composition and enjoy the relief that comes with knowing exactly what’s happening beneath the surface of your weight.

Happy Losing!