Muscle for Life with Mike Matthews - How to Calculate Your Body Fat Percentage Easily & Accurately

Episode Date: June 3, 2019

In this podcast, I want to share what I've learned on calculating body fat percentage, including ... What “body fat percentage” means. The pros and cons of popular ways of calculating body fat pe...rcentage. How to determine your body fat percentage with a fair amount of accuracy. Why obsessing over body fat percentage is counterproductive (and what to do instead). And more. Let's get started. 5:37 - What is body fat percentage? 6:56 - What’s the difference between body fat percentage and body mass index? 8:56 - Can you determine your body fat percentage based on your body mass index? 11:09 - What is a healthy body fat percentage for men and women? 23:09 - What are the different ways to measure body fat percentage and how accurate are they? 37:07 - How do you calculate body fat percentage? 44:01 - What is the best way to reduce body fat percentage? Want to get my best advice on how to gain muscle and strength and lose fat faster? Sign up for my free newsletter! Click here: https://www.muscleforlife.com/signup/

Transcript
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Starting point is 00:00:00 Hello, hello, hello. I am Mike Matthews and welcome to another episode of the Muscle for Life podcast. This one is going to be all about body fat percentage, which I thought I had spoken about previously and was surprised to learn that I had not done an episode on measuring body fat percentage yet. So here it is. And me thinks it will be one of the more popular episodes that I've done in a bit because measuring or estimating body fat percentage can be pretty confusing. My first experience with this was several years ago when
Starting point is 00:00:43 I got very lean for a photo shoot, somewhere around what I would have thought was six or 7% body fat. Competitors step on stage around four to 5%. I wasn't that lean, but I was getting there. I had ab veins. I couldn't pinch any fat really anywhere on my body and everything just looked sharp and defined. And so I tried measuring my body fat and my score was 11%. And it's not that I really cared about the number. Ultimately, what you see in the mirror is what matters. And I looked great. I looked about as great as I can possibly look. So if that was 11%, then it was 11%. But it still didn't quite make sense because again, I looked like I could have
Starting point is 00:01:32 stepped on stage maybe as a physique athlete, for example, not bodybuilder shredded, not shredded glutes shredded, but very, very lean. And if that was 11% and to get bodybuilder lean, I would need to lose, let's say another 6% body fat, or let's see, cause I was weighing about, I think 185 at the time. So that means that to get body builder lean, I would have to lose another 11 pounds of fat, 11 pounds. I mean, imagine a pound of fat is like a solid handful of fat. And looking at my body, I literally had no idea where all that would come from. Again, I was assuming that I was maybe five pounds of fat away from bodybuilder lean. And the way that I came to that measurement was the standard bodybuilder approved multiple point caliper test,
Starting point is 00:02:27 which we did several times just to confirm each of the measurements. And so according to that measurement, I was still carrying around 20 pounds of fat on my body, total, total body fat, 20 pounds. And so it was confusing because where was all this phantom fat hiding? I couldn't pinch anything more than like skin anywhere on my body. And also considering what it took to get that lean, if that was really 11%, I guess even 7%, let alone 5% would have just been impossible. I had dieted for a couple months and was feeling okay, but it was definitely starting to take its toll in terms of energy levels, sleep, sex drive, workouts, and so forth. And so I then set out to learn what was really going on. And in this
Starting point is 00:03:22 podcast, I'm going to share what I've learned, including what body fat percentage is, the pros and cons of various popular ways of calculating body fat percentage, how to determine your body fat percentage with a fair amount of accuracy, why obsessing over body fat percentage is counterproductive and what you should do instead, body fat percentage is counterproductive and what you should do instead and more. This is where I would normally plug a sponsor to pay the bills, but I'm not big on promoting stuff that I don't personally use and believe in. So instead, I'm just going to quickly tell you about something of mine, specifically my fitness book for women, thinner, leaner, stronger. Now this book has sold over 150,000 copies in the last several years, and it has helped thousands of women build their best bodies ever, which is why it currently
Starting point is 00:04:13 has over 1,200 reviews on Amazon with a four and a half star average. So if you want to know the biggest lies and myths that keep women from ever achieving the lean, sexy, strong, and healthy bodies they truly desire. And if you want to learn the simple science of building the ultimate female body, then you want to read Thinner, Leaner, Stronger today, which you can find on all major online retailers like Audible, Amazon, iTunes, Kobo, and Google Play. Now, speaking of Audible, I should also mention that you can actually get the audiobook 100% free when you sign up for an Audible account, which I highly recommend that you do if you're not currently listening to
Starting point is 00:04:56 audiobooks. I myself love them because they let me make the time that I spend doing things like commuting, prepping food, walking my dog dog and so forth into more valuable and productive activities. So if you wanna take Audible up on this offer and get my book for free, simply go to www.bitly.com slash free TLS book. And that will take you to Audible. And then you just have to click the
Starting point is 00:05:26 sign up today and save button, create your account. And voila, you get to listen to thinner, leaner, stronger for free. Alrighty, that is enough shameless plugging for now, at least let's get to the show. All right. So let's start with what is body fat percentage? Well, your body fat percentage is exactly that. It is the percentage of your body weight that is fat. So for example, if you weigh 150 pounds and you have 15 pounds of fat on your body, your body fat percentage is 10%, right? 15 divided by 150. And this means that your body fat percentage is a moving target because it changes when you gain fat, it changes when you lose fat, and also when you gain and lose muscle. So for instance, if you used proper diet and weightlifting to increase your weight from,
Starting point is 00:06:17 let's say, 150 to 170 pounds with just five pounds of additional fat gain, your new body fat percentage would be about 12% because now you have 20 pounds of fat divided into 170 pounds of total body weight. And then let's say that you stopped lifting for a year or so and lost 10 pounds of muscle, but no fat, your new body fat percentage would still be around 12% because you have 20 pounds of fat divided into 160 pounds of body weight. So the point is your body fat percentage ebbs and flows as you change your body composition. Okay, so next I want to talk about body fat percentage versus BMI because I often get asked about this and many people mix these things up, but they are completely different. So BMI stands for body mass index, and it is a
Starting point is 00:07:13 numeric expression of the relationship between your height and your weight. Now you calculate your BMI by dividing your weight in kilograms by your height in meters squared. So for example, my BMI when I was 185 pounds and super lean was about 25. Now, according to BMI data, that would put me in the overweight category because BMI values are correlated with different body weight statuses. So underweight would be a BMI under 18.5. Normal weight is 18.5 to 24.9 and overweight 25 to 29.9 and obesity would be 30 and above. So according to that, I was borderline overweight. I was just in the beginning phase of being overweight despite being pretty shredded, which of course is silly. And that is the rub with BMI. It is useful for analyzing broad populations and also sedentary people or people
Starting point is 00:08:18 who maybe exercise, but who don't train their muscles at all. But it is not very useful for those of us into fitness, and especially into any type of resistance training. Because of course, muscle weight is not distinguished between body fat weight. And as I carry around a lot more muscle than the average person, about probably 40, 45 pounds more than the average person. This bumps up my BMI quite a bit, despite having a low body fat percentage, very low at the time of when I was looking into all this. And even now, currently I'm probably around 11% or so, which is still quite a bit lower than the average person. Another thing I am often asked about is determining body fat percentage based on BMI. Can you do that? And the answer is no. Most people can't because as BMI is solely based on your height and weight, it does not
Starting point is 00:09:13 take into account how much of that weight is fat versus muscle. And what that means is BMI can be high for different reasons. On one hand, it can be high because like me, you are a pretty muscular person and you're also fairly lean. On the other hand, it can be high because of the exact opposite. It could be high because the person has a low amount of muscle or maybe even an average amount of muscle, but a lot of body fat. That said, there is one situation where you can use BMI to at least roughly estimate someone's body fat percentage. And that is in overweight people with normal levels of muscle mass. So people who don't train their muscles regularly. And in that case, BMI is actually often similar to body fat percentage. So for example, a guy who's let's say 5'10", 200 pounds, 30% body fat would probably have a BMI of about 30.
Starting point is 00:10:08 And likewise, a 5'4", 160-pound woman at 40% body fat would probably have a BMI of about 40. This correlation disappears, though, when you start looking at lean people. So for example, my body fat percentage is typically around 10%, give or take a percent or two, but I would have to starve myself to a life-threatening 76 pounds or just a dead 76 pounds to get a BMI of 10 or 11 or 12. This relationship also disappears with people with above average muscularity. My BMI was 25 when I was very lean, but my body fat percentage was less than a third of that. And this is why I never recommend that people use BMI to estimate body fat percentage, even if it kind of sort of
Starting point is 00:10:59 works in some situations. Even then, there are better ways to estimate body fat percentage. Alrighty, so that's it for BMI and body fat percentage. And next on my list of things to discuss is what is a healthy body fat percentage for men and women? Because as much as it is generally despised, body fat is much more than a layer of ugly, unwanted, greasy flesh to be eradicated as thoroughly as possible. Hey, before we continue, if you like what I'm doing here on the podcast and elsewhere, and if you want to help me help more people get into the best shape of their lives, please do consider picking up one of my best-selling health and fitness books. My most popular ones are Bigger, Leaner, Stronger for Men, Thinner, Leaner, Stronger for Women, my flexible dieting cookbook, The Shredded
Starting point is 00:11:59 Chef, and my 100% practical hands-on blueprint for personal transformation, the little black book of workout motivation. Now these books have sold well over 1 million copies and have helped thousands of people build their best body ever. And you can find them anywhere online where you can buy books like Amazon, Audible, iTunes, Kobo, and Google play, as well as in select barnes and noble stores so again that is bigger leaner stronger for men thinner leaner stronger for women the shredded chef and the little black book of workout motivation oh and one other thing is you can get any one of those audiobooks 100 free when you sign up for an audibleudible account. And that's a great way to make those pockets of downtime, like commuting, meal prepping, and cleaning more interesting, entertaining,
Starting point is 00:12:50 and productive. Now, if you want to take Audible up on that offer and get one of my audiobooks for free, just go to legionathletics.com slash Audible and sign up for your account. slash audible and sign up for your account. Body fat actually plays many vital roles in the body, including protecting organs from damage, maintaining body temperature, producing various hormones like leptin and other chemicals and much more. And that's why there's a limit to how lean you can get before your health starts to decline. What is that limit though? Well, first let's start with some classifications of body fat percentage ranges. So in men, the essential range is four to 6%. The athlete range is 7% to 10%. The fit range is 11% to 16%. The normal range is 17% to 25%. And the overweight, eventually obese range is 26% and above. And in women, it looks like this.
Starting point is 00:13:58 The essential range is 10% to 12%. The athlete range is 13% 20 percent. The fit range is 21 to 24 percent. Normal is 25 to 31 percent. And overweight slash obese is 32 percent and above. And in case you are wondering, the additional fat that women carry in their breasts, hips, thighs, and butts accounts for their generally higher body fat percentages and higher ranges. Now, studies show that the absolute leanest men can get under any circumstances is about 4% to 5% body fat. You try to go beneath that, you die. And the leanest women can get is about 10% to 12% body fat. That's why it's called that essential body fat range. And the leanest women can get is about 10 to 12% body fat. That's why it's called that essential body fat range. And the reason for this is once you get this lean, all that's left is small amounts of body fat stored in nerve cells, brain tissue joints, and the pads of your
Starting point is 00:14:58 hands and palms of your feet, and covering major organs like the heart and intestines. This is the body fat that is required to stay alive. So when someone hits this essential body fat range, which it has been done, and there are plenty of examples on the internet of beyond shredded, like shredded to the bone, almost literally bodybuilders out there who have done it. And when they do this, they are taking their lives into their hands. Their lives are literally on the line because if they keep losing fat, eventually their heart can stop or they can fall into a coma, which is why actually your body starts to protect itself by beginning to break down muscle tissue and then internal organs for energy instead of burning the last bits of essential body fat. And this is why studies
Starting point is 00:15:52 show that people who die of starvation still have most of their essential body fat. Now, you might be scratching your head at this point because of some of the sweet body fat brags that you have seen on social media or maybe heard in the gym. For example, I've heard guys in the gym in the locker room say that they got down to 2% body fat for their competition. And I've heard women claim five or 6%. Now, as you know, this is physiologically impossible. How can these people be so off though in their estimations? Well, usually it's just willful ignorance or outright lying, but sometimes it's because the methods they use to measure their body fat percentage are wildly inaccurate, and especially in people who are lean. And we'll talk more about that in a minute.
Starting point is 00:16:46 And just for the sake of reference here, if you want to see what four or 5% body fat really looks like, search for a dude named Helmut Strebel, H-E-L-M-U-T-S-T-E-B-L. And you will find pictures of the most shredded dude you've probably ever seen in your life. That's what four or 5% body fat looks like on a guy. Now, if you want to see what 10-ish percent body fat really looks like on a woman, search for it's a Daily Mail article, the British tabloid, I think it is. And the title is Ripped Female Bodybuilder with an Incredible 0% Body Fat Shows Off Her Trim Physique But Sparks Debate Over Whether She's Healthy. Now, of course, she doesn't have 0% body fat, but she is absolutely shredded. And that's what 10% or so looks like on a woman. And my advice to you here is, even if you
Starting point is 00:17:46 think it looks cool, unless you are a competitive bodybuilder and unless you know exactly what you're doing with your body and why, do not ever try to get this lean. Your hormones are going to go haywire. Your organs can fail. And even when you avoid disaster, the road back to normality can be quite long and bumpy. There are case studies out there of natural bodybuilders dealing with hormonal abnormalities a year after competing. Now, I'm sure they made mistakes along the way in terms of their prep and post-competition, off-season, but still, it's pretty impressive how much getting and staying really lean can mess up your body. Now, fortunately, you are probably like most people and you'd never want to get that lean. Instead, you probably just want to be in the lower end of the
Starting point is 00:18:38 athletic range, or maybe even just in the middle of the athletic range, right? So for men, that's 7% to 10%. And for women, that's 13% to 20%. And this is what most people would consider ripped or shredded. Most guys are going to be happy really at 10%, honestly. And if they want to get really lean, they maybe get down to like 8%. And for women, most are happy around 20% if they just have muscle in the right areas of their bodies. And if they want to be really lean, maybe they take 18% or so. And if you want to see what those body fat percentages look like for the men, just search for some shirtless pictures of Cristiano Ronaldo. I'm not sure if I'm pronouncing his first name right, but the famous soccer guy. He is usually around, most of the pictures I've seen, probably around 7% or 8%. He's very lean.
Starting point is 00:19:25 If you want to see the equivalent for women, probably somewhere around 17% body fat or so, search for Jessica Ennis, E-N-N-I-S. And you'll find there are a few famous pictures of her holding up the British flag. And that's what 17% or so looks like on a woman. And that's what 17% or so looks like on a woman. And in case you're wondering, I'm talking about elite athletes here simply because there's a lot of high quality research on them. This is why we know, for example, that top male athletes in many different sports are usually around 6% to 10% body fat and the females are usually around 13% to 20% or so. And the good news is anyone can look like Ronaldo or Ennis with proper dieting and exercise. It is not pleasant to try to maintain that look for very long periods of time, unless you are very, very active like an athlete, which allows you to eat more food and is just better on your body than trying to stay very lean on smaller amounts of food. But it can be done if you are willing to strictly control your calories. And unfortunately, that can be hard when you are fighting against your body's natural desire to be fatter, really.
Starting point is 00:20:39 Your body does not want to be 7% or 8% body fat or 16% or 17% if you're a woman. It would much rather be probably closer to 10% to 15% if you're a man or 20% to 25% if you're a woman. And if you want to learn more about why, search for the podcast, just search for my feed for Setpoint, and you'll find an episode that I recorded on this specifically. So while that's the case with the lowest levels of that athletic range, 7% in men and let's say somewhere around 15% in women, the good news is you can maintain slightly higher levels of body fat, at least most people can, while still being able to enjoy life, eat foods that you like. You can't eat whatever you want, whenever you want, of course, but have good workouts and be healthy. Now, it is not necessary
Starting point is 00:21:31 to be that lean to be healthy. Generally speaking, the health benefits of fat loss drop off around 15% body fat in men and around 20% in women. So you can be more or less just as healthy as a guy at 15% as you can at 10% or even 8%. And the same for women at let's say 25, 20 or 18%. And so the only real reason to bring your body fat percentage below the fit range into the athletic range or the athlete range, especially the athletic range or the athlete range, especially the lower levels of the athlete ranges. It's about vanity really, and just feeling better about how you look rather than improving your health. And that's okay. I think that's a perfectly valid reason to do it. In fact, I think everybody should do it at least once because it is
Starting point is 00:22:20 cool. It's not very hard. If you know what you're doing, you just got to stick with it. It's not the most enjoyable thing. You will have to deal with some hunger and deal with some cravings probably, but if you know what you're doing, it's going to be pretty smooth sailing. And especially if you incorporate something like calorie cycling and diet breaks, which you can learn about either on my podcast here. I recently published an episode on calorie cycling, so you can search my feed and learn about that. And I don't think I've done an episode on calorie cycling, so you can search my feed and learn about that. And I don't think I've done an episode on diet breaks yet. Oh no, I did. I recorded an interview with James Krieger. So if you search for Krieger, K-R-I-E-G-E-R, I believe diet breaks
Starting point is 00:22:57 is probably in the title as well. So you can learn about those things there. So my point is, if you incorporate calorie cycling and diet breaks into the later phases of the diet, when let's say if you're a guy and you're at about 10% and now you're going to make that final push to get to 7% or 8%, or if you're a woman and you're at 20%, you're going to make that final push to get down to the 17%, 18% range, incorporating calorie cycling and diet breaks can make it even easier and just more enjoyable, less painful. And so my point with that is you do it right and you can take a bunch of pictures. You can enjoy it for a bit.
Starting point is 00:23:30 I wouldn't recommend trying to stay there for extended periods of time, but it is fun. Now, once your body fat levels rise above the fit range, that's when you start to look overweight. And I generally recommend that people do not exceed that range of body fat because it starts to get unhealthy, it slows down muscle growth, and it's going to make any later efforts to get lean longer and grueling. When you have six months of dieting ahead of you, that is a lot more daunting than three months. All right. So now let's talk about calculating body fat percentage. How do you do it? Well, there are quite a few
Starting point is 00:24:11 ways of doing it and you can get quite a few different results based on what you do. So in my case, the multiple point caliper test that I was talking about in the beginning of this podcast said I was 11% body fat, but then the handheld device in the gym said I was 8%. And a different method, a single point caliper said 6%. So what gives? Well, let's go down the list here. Let's talk about body composition scales and handheld devices first, because they are the simplest way to measure your body fat percentage. You step on the scale, you hold the device, you get a number. Now, these instruments use a method called bioelectrical impedance analysis, BIA, which involves measuring your body's resistance to a light electrical current. Muscle conducts electricity very well because it is over 70%
Starting point is 00:25:02 water and fat does not because it holds much less water. Thus, the more resistant the body is to an electrical current, the fatter it must be. That's the logic behind the method. And it sounds reasonable enough, but there are some serious problems with BIA. First, electricity takes the path of least resistance. So as the current passes through your body, it will actually avoid fat stores for tissues that are easier to traverse. So internal tissues will be chosen over subcutaneous fat, for example. And making matters worse is the fact that two electrode devices like scales, or at least most scales and handhelds, skip entire portions of your body. The foot-to-foot scales miss your entire torso and hand-to-hand devices miss the
Starting point is 00:25:54 lower half of your body. And as you can imagine, this corrupts the results. Another problem with BIA is it uses mathematical equations to turn the raw readings of the devices into body fat percentages. And these equations can be very flawed. You see, when a company develops a BIA device, they calibrate it using another imperfect method of measuring body fatness, like hydrostatic weighing. And there are several steps involved in this process. So what they do is they measure the body fat of a large group of people with the control method. So in this case, it would be the hydrostatic weighing. And then they would measure again with the BIA device. They would compare the readings and then they would develop an equation
Starting point is 00:26:42 to predict BIA results based on height, weight, gender, and other variables. And this is not a bad approach. It could work if the control methods readings were accurate, but unfortunately, they are often not. So in other words, many companies are calibrating their BIA devices to conform to incorrect calculations of body fat percentage. Hydrostatic weighing is the one that is most frequently used for BIA benchmarking, and studies show that it can be off by as much as 6%, and that's in an absolute sense, not relative sense, for a number of reasons relating to ethnicity, body weight, hydration status, and more. And again, if 6% doesn't sound too bad for you, I'm talking about absolute, not relative. So if someone is actually 10% body fat,
Starting point is 00:27:31 they may register at anywhere from 4% to 16% body fat with hydrostatic weighing. Another problem with BIA devices is body conditions can dramatically influence readings. So for example, if you test your body fat with a BIA device when you are dehydrated, you are going to read abnormally high due to lower conductivity in the body. If you were to test after eating, you would see the opposite effect. You would read abnormally low. For example, in one study, being fed reduced readings by 4.2%. Research also shows that the body is more conductive after exercise. So if you were to test after a workout, you would get another artificially low reading. And these are some of the reasons why scientists
Starting point is 00:28:19 have said that consumer level BIA devices are just not suitable for accurately estimating body fat percentage. Now, what about using one of these devices for tracking changes to your body fat over time? If BIA were at least consistently inaccurate, that might work, right? At least for determining whether your body fat percentage is going up or down. And sure, but unfortunately, these devices are just too all over the place for even that. So they have really no good use. All right, let's move on to body fat calipers and skin fold testing. Now, skin fold testing uses calipers to measure the thickness of your skin at various points in your body and the measurements are added together and then fed through a couple of equations that ultimately give you a body fat percentage.
Starting point is 00:29:11 And I think you might see where this can go wrong. Namely, if you pinch too little skin, you're going to read lower than you are. If you pinch too much skin, you're going to read higher. And then beyond pinching, there is the problem of bad equations, bad math. So for example, in one study, a team of scientists at the VA Medical Center in Durham, North Carolina took skin fold measurements of 681 healthy men and women. And as a control, they also measured everyone's body fat percentage using a far more accurate technique known as the four compartment model, which we will talk more about in a bit. And what the researchers found is that the skinfold measurements were about as accurate as the four compartment model for measuring the average body fat percentage of the entire group. But when it came to individuals, the skin fold measurements were very wrong for many of the participants. In many cases,
Starting point is 00:30:13 the skin fold measurements either over or underestimated body fat percentage by as much as 10 to 15%. And yes, that's absolute. So a guy at 20% body fat, he might get a reading of 5% body fat, stage shredded, or 35% body fat obese using the skinfold methods in the study. In another study, skinfold testing produced measurements that ranged from 5% too low to 3% too high. And another study that was conducted with bodybuilders demonstrated similar error rates. So the upside to skinfold testing is this. Some methods are more accurate than others and do lend themselves well to tracking changes to body fat levels over time. And we'll get to that in a few minutes. Next on my list for estimating body fat percentages, pictures, and the mirror. And this is the simplest and the most
Starting point is 00:31:12 obvious way to guesstimate your body fat percentage. Most people around a certain body fat percentage look similar if they have similar amounts of muscle. If they don't, then the same body fat percentage can actually look quite a bit different on two different physiques. So for example, a 160-pound guy at 10% body fat has 16 pounds of fat, whereas a 190-pound guy at 10% has only three pounds more fat, but quite a bit more muscle, giving him a very, very different look. Now, if you are still listening to this, chances are you are into working out and you probably have a bit more muscle than the average guy or gal. So if you'd like to see a chart that would allow you
Starting point is 00:31:58 to quickly estimate your body fat percentage, just search for Legion Athletics body fat percentage, and you'll find an article that I wrote that this podcast is based on. And there is a chart in there for guys and for women that shows everything from four to 5% to 35 to 40% for men and 12 to 14% to 50% plus for women. And if you go check out those charts, you'll see that the coveted six-pack emerges around 10% body fat in men and about 20% in women. And abs slash core vascularity starts to become visible around 8% in men. Genetics do play a role here. Some people are just naturally vascular and some people are not. I am not, for example. Abvascularity for me does not really start to show until probably 6% or 7%. But in women, abvascularity starts to show around 15% in most women, maybe a little bit lower than that. And the kind of carved out of stone
Starting point is 00:33:06 look is about 6% in men and 11 or 12% in women. All right, let's move on and talk about the next method of estimating body fat. And that is dual energy x-ray absorptiometry or DEXA. And this is a technology that uses a full body x-ray to help calculate your body fat percentage. And the scientific basis of this method is that fat and fat-free mass absorb x-ray energy differently, which then allows each of these elements to be isolated and measured. And that sounds like it should be very accurate, right? And most people do indeed think that DEXA readings are unerring. If the DEXA says that the dude is 7%, he is 7%, end of story. But research shows otherwise. Ironically, DEXA can be just as inaccurate as
Starting point is 00:34:00 any of the other methods that we've discussed so far. For example, in two studies, the individual error rates using DEXA were as high as 4%. And again, that's in an absolute. So somebody at 10% could read at 6% or 14%. In another study, the DEXA was off by 8 to 10%. And that helps explain why many bodybuilders in contest shape have been a bit perplexed by their DEXA readings of anywhere from six to 10 percent body fat. You know, when you are a guy with dick skin everywhere on your body, as the bodybuilders like to say, literally there's no fat left. You just pull skin off of your muscles and you go and DEXA at 10%, you got to wonder, right? And there are several reasons for DEXA's fallibility. The results can differ between
Starting point is 00:34:50 machines, both from the same and different manufacturers. The accuracy is affected by gender, body size, body fatness, and even disease state. Different machines use different algorithms to interpret the raw data from the body scans, and some are just better than others. Even the type of x-ray used, fan versus pencil beam, influences the accuracy of the test. And so does how hydrated you are. That can greatly affect the results. So the bottom line here is, as with the other methods we've discussed so far, like BIA and skin fold testing, Dexascan can give you an accurate calculation of your body fat percentage, but it can air instead of water. So what you do is you sit in a seated chamber and then sensors measure the amount of air that your body displaces. And then mathematical formulas are used to translate the readings into body composition statistics. Now we already know how inaccurate hydrostatic weighing can be. And unfortunately, research shows that the BOD pod seems to be even
Starting point is 00:36:07 worse. Its accuracy is affected by more variables like facial hair, moisture, body temperature, and even the tightness of the clothing that you're wearing when you are sitting inside the device. So for example, in one study, BOD pod readings were off by as much as 15%. And in other studies, error rates of 5% to 6% were seen. And that research helped explain for me some of the rather shocking bod pod readings that I've seen working with others. I've come across dozens of people in my travels whose bod pod measurements were easily double their actual body fat percentages because you don't need more than eyeballs to know that a dude around 10% is not around 20%. All right, so those are the most popular methods that people use to calculate or estimate body fat percentages. And obviously they all have serious flaws. So
Starting point is 00:37:08 how do we do it then? How do we calculate our body fat percentage? Now, I mentioned something earlier, which is this four compartment analysis. And this is how scientists were able to determine the error rates of the various testing methods that we've gone over. They checked BIA, dexabod pod, hydrostatic, and skinfold results against the four-compartment analysis, which is the gold standard of body fat calculation. And this method involves using several testing methods to piece by piece separate body weight into four categories, bone, water, muscle tissue, and fat mass. So for example, hydrostatic weighing is used to measure body density, deuterium dilution is used to measure total body water, and DEXA is used to measure
Starting point is 00:38:03 total bone mass. And then the data that's collected from each of those tests is manipulated with various equations and the result is a consistently accurate measurement of body fat percentage. Now, this is nice to know, but it's not very useful for most of us because it requires a team of scientists. Fortunately, however, there is a method of calculating and tracking body fat percentage that I feel is fairly accurate and consistent enough to warrant the time and attention. And this is how I do it myself. So what I do when I want to keep close tabs on my body fat percentage, so let's say when I'm cutting or when I'm lean bulking is I use calipers, a
Starting point is 00:38:46 scale, a measuring tape, and the mirror. So let's go over these things, not necessarily in that order. Let's talk about the scale first. So what I do is I weigh myself every day, and then I calculate an average weight every seven to 10 days. And the reason I do it this way is your weight can fluctuate from day to day due to things that you can't see or even necessarily control like water retention, glycogen storage, and bowel movements. And this is why you don't want to put too much stock in daily weight measurements. Your weekly weight averages are much more useful because they give you a much truer picture of what is actually happening with your body weight. Because if your seven to 10 day averages are going up over time, you are gaining weight.
Starting point is 00:39:35 Some people also do even bi-weekly. They like to average every other week as well. But anyways, if the average is going up, you're gaining weight. If the average is going down, you're losing weight, regardless of what the day-to-day is doing. So weigh yourself every day, first thing in the morning after the bathroom and before any food or water, record your daily weights and then take an average every seven to 10 or maybe even 14 days. And of course you do that by just summing the daily weights and then dividing by the number of days and then watch those averages. And then you won't need to fret over temporary movements up or down in your body weight. All right, let's talk about caliper measurements and taking bi-weekly caliper measurements. So generally speaking, if your
Starting point is 00:40:11 skin is getting thicker over time, you are gaining fat. And if it's getting thinner, you are losing fat because of course, most of the fat that we are gaining and losing is subcutaneous fat. It is the fat underneath the skin. And this is why caliper readings can be useful despite being not very reliable for determining body fat percentage. Now, I've tried many calipers and skinfold testing methods. And the one that I've found best that I have liked the most is from a company called AccuMeasure, A-C-C-U measure. And if you go on Amazon, you can find something called the AccuMeasure Fitness 3000 body fat caliper. That's the caliper I like to use. I'm not getting paid to recommend that, but that is just the one that I
Starting point is 00:40:55 like and use. And there are two reasons why I like it. One is it's a simple one site testing method, which means there are less ways to screw it up. And two, it's actually surprisingly accurate. Again, I don't recommend only going off of this reading, but I've used it quite a bit myself and I've worked with a lot of people using it, and I rarely see flagrant misestimations. It usually seems to be accurate to within a couple percent. And in terms of how to use it, you can just follow the instructions. Again, it's a one site method, so it's pretty easy to use. And I used to personally, and I used to recommend doing weekly caliper measurements to coincide with weekly waist measurements and progress pictures. But I stopped doing that because skin fold thickness tends to change slower than other measurements. So typically you'll only notice maybe a millimeter or two of difference from
Starting point is 00:41:51 one week to the next, which can be easily missed by just placing the calipers in a slightly different spot or not pressing down as hard as you did last time or whatever. Another reason why I started doing bi-weekly and not weekly is taking caliper measurements does take longer than taking waist measurements and progress pictures. And most people to kind of just get tired of doing it every week. And especially when the changes are so subtle and it's not vital, you could take no caliper measurements and you'd be okay. But I figured I'd mention it because a lot of people do like to do calipers. So there it is. Bi-weekly, that gives you enough time to see more significant and less error-prone
Starting point is 00:42:32 changes in your skin fold thickness. Let's talk about waist now. I recommend taking weekly waist measurements when you want to keep an eye on your body fat percentage because the size of your waist measured at the navel is a reliable indicator of fat gain or fat loss. An ever-expanding waist indicates fat gain, an ever-shrinking one indicates fat loss. And that's why it is a good measurement to keep an eye on. And of course, all you need is a simple measuring tape. Lastly, we have pictures. I like to take weekly pictures. And if you're like most of us, gym goers, the point of all of this, for the most part, is what you see in the mirror. And I'm just as guilty as everybody else. And the problem though is when you look at yourself every day in the mirror, you can get discouraged because you are not seeing the gradual improvements.
Starting point is 00:43:27 If you take weekly front side and back pictures, though, in good front on lighting in the same position, same spot every time, of course, it helps greatly with seeing your progress and staying motivated. So that's it. That's how I recommend keeping an eye on your body fat percentage and estimating it. You can use the charts in the article and just compare to what you see in the mirror. You can use the caliper. That should probably also, the one that I recommended should also give you a fairly accurate estimate. And then you just keep
Starting point is 00:44:00 tabs on how things are changing from there. Now I want to, before we wrap up here, talk about the best way to reduce your body fat percentage, because there are actually two ways to do this. Of course, if you lose body fat while maintaining muscle mass, your body fat percentage is going to go down. That's obvious. But a lot of people don't consider that if you increase your muscle mass while minimizing your fat gain, that also decreases your body fat percentage. Now, when you run the numbers, though, you quickly see that the fat loss option is far more effective for reducing your body fat percentage than the muscle gain one. And the reason why is when you know what you're doing with your diet and your exercise,
Starting point is 00:44:43 you can expect to lose around, let's say a pound or so of fat per week. It might be a little bit less if you're lean, wanting to get really lean. It might be a little bit more if you're overweight. When you are lean bulking though, the best you can hope for after your newbie gains are gone at least is maybe a half a pound to a pound of muscle per month with about the same amount of fat gain. And furthermore, that target for muscle gain becomes smaller and smaller as you near your genetic potential for muscle growth until it finally just becomes vanishingly small. So for example, let's say that you weigh 150 pounds at 15% body fat. So you're a guy, 150 pounds, 15% body fat, and this
Starting point is 00:45:27 gives you 127.5 pounds of lean mass and 22.5 pounds of fat mass. And then let's say that you lean bulk successfully for a year and you gain 10 pounds of muscle and 10 pounds of fat, putting you at 137.5 pounds of lean mass and 32.5 pounds of fat mass for a total body weight of 170 pounds. If you divide the fat mass by the total body weight, you get about 19% body fat. And what you have learned then is despite gaining 10 pounds of muscle, which is very, very good for a year if you're not brand new, with pretty minimal fat gain, you are still quite a bit fatter than you were before the gaining phase. Now let's see what the numbers would look like if you decided to reduce your body fat percentage by cutting. So again,
Starting point is 00:46:19 let's say that you weigh 150 pounds and 15% body fat, 127.5 pounds of lean mass, 22.5 pounds of fat mass. You cut, you lose 10 pounds of fat without losing muscle, which you definitely can do. You're going to lose some water weight and some glycogen weight, which may register as lean mass, but you didn't lose any actual muscle tissue. So that brings your body weight down to 140 pounds, and you still have your 127.5 pounds of lean mass and 12.5 pounds now of fat mass, which becomes about 10% body fat. Now, I know the lean mass would be a little bit less due to water and glycogen depletion, or at least reduction, but I'm just keeping the number simple to make a point here. And that is that cutting reduced your body fat percentage by 50%, relatively speaking, of course.
Starting point is 00:47:06 You cut it in half, and it did that in a quarter of the time that it took to build 10 pounds of muscle. Now, of course, that is not to say that building muscle is not going to improve your physique, of course, but it will not have the same effect on your body fat percentage and your appearance as quickly as losing fat will. Well, those are all the key things I wanted to cover in today's podcast. So let's just run back through the highlights. So your body fat percentage is just the percentage of your body weight that is fat, and it is a better measurement of your overall health, fitness, and body composition than BMI. And it's also useful for setting weight loss goals. A healthy body fat percentage for men is somewhere between 8% and 16% body fat. And a healthy body fat percentage for women is something between 16% and 24%. And I've found after working with thousands and thousands of people over the years that most
Starting point is 00:48:05 men are happiest somewhere around 8 to 12% body fat. And most women are happiest somewhere around 18 to 22% body fat. Yes, you can get a bit leaner, but it's usually not worth the trouble. It can be fun. You can get some pictures. You can brag. But in the end, you are probably going to find that you just enjoy life more when you're a little bit fatter. Now, speaking of bragging, there are many people out there who brag about their supposed super low body fat levels. But the only way to know your body fat percentage with absolute certainty is to remove all of the fat from your body and weigh it. And I doubt even the most narcissistic of the bunch are going to volunteer for that. So with autopsy off the table and four compartment analysis out of reach for
Starting point is 00:49:00 most of us, the bottom line is that body fat calculations themselves aren't just not as important as how they are changing over time. And this is why I don't bother with inconvenient and expensive testing methods like DEXA or the BODBOD. You may or may not get an accurate reading, so why bother? Instead, you can just use your weight, your skin fold results, your waist measurements, and your pictures to know exactly what is happening with your body. Hey there, it is Mike again. I hope you enjoyed this episode and found it interesting and helpful. And if you did, and don't mind doing me a favor and want to help me make this the most
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Starting point is 00:50:25 reach out. All right, that's it. Thanks again for listening to this episode and I hope to hear from you soon. And lastly, this episode is brought to you by me. Seriously though, I'm not big on promoting stuff that I don't personally use and believe in. So instead I'm going to just quickly tell you about something of mine, specifically my fitness book for women, Thinner, Leaner, Stronger. Now, this book has sold over 150,000 copies in the last several years, and it has helped thousands of women build their best bodies ever, which is why it currently has over 1,200 reviews on Amazon with a four and a half star average.
Starting point is 00:51:07 over 1,200 reviews on Amazon with a four and a half star average. So if you want to know the biggest lies and myths that keep women from ever achieving the lean, sexy, strong, and healthy bodies they truly desire, and if you want to learn the simple science of building the ultimate female body, then you want to read Thinner, Leaner, Stronger today, which you can find on all major online retailers like Audible, Amazon, iTunes, Kobo, and Google Play. Now, speaking of Audible, I should also mention that you can actually get the audio book 100% free when you sign up for an Audible account, which I highly recommend that you do if you're not currently listening to audio books. I myself love them because they let me make the time that I spend doing things like commuting, prepping food, walking my dog, and so forth into more valuable and productive activities.
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