Body Composition: More than appearance, a health factor that should not be over looked!

Body Composition: More than appearance, a health factor that should not be over looked!

When you walk in the doctor’s office, you are asked to take your shoes off so they can get an accurate weight and measurement of how tall you are. The nurse takes both of the measurements and does the simply equation in seconds to figure out your BMI or body mass index. All the nurse does is take 703 times your weight/ by your height to get this magic number. Your doctor then comes in a half hour later and yells at you cause your number is too high. You start questioning yourself, looking around for answers, asking yourself what does this number really mean?

In modern day medicine, the common body composition measurement is BMI. BMI is often the worst tool is measuring weight because it does not factor in frame size, water weight, or differentiate between fat and muscle mass. All BMI is telling you is you are either too much mass or too little mass, not telling you what makes up that mass.

So, what is Body Composition, why does it matter, and how can we accurately test it?

Body composition is often referred to and defined as the relative proportion of fat and the fat-free tissue that is in the body, which is therefore called the percent body fat. Body composition is important to health professionals for three major reasons: a factor in sports performance, correlated with many health risks, and helps establish a target or desirable weight for an individual. First, body composition can influence performance on a lot of fitness tests because it can affect an athlete’s strength, agility, and appearance. An individual with a lean body mass will have an advantage in sports where speed is a factor. Second, scientific research has shown a strong correlation between high levels of visceral body fat and an increased risk of chronic diseases such as diabetes, hypertension, and other chronic illnesses. The third and final reason fitness professionals incorporate body composition testing for individuals is the factor that it is a great way to establish goals and an optimal appearance for a client. Body Composition is a very influential factor in an individual’s health from health risks to performance outcomes to an individual’s overall confidence. There are seven different body composition tests available and in this article, I will explain the pros, cons, possible errors of each, and rank them from worst to best. The factors that I will rank them on is accuracy of measurements, convenience for the user, repeatability of test measurements, and depth of information given from each test.

  1. BMI

BMI or Body Max Index comes in at last place, which should not be a shock to most. First, BMI has zero accuracy when it is measured because you cannot even tell the fat mass apart from the muscle mass. The convenience and repeatability with BMI are great, but again it does not even answer the first and simplest question of body composition, what makes up this mass? This also ranks last because there is no information that is given to the patient. You are told you are either too much, too little, or just the right amount of mass.


  1. Skinfold

Skinfold is one of the most common and widely used body composition tests. The most popular skinfold tests are either the 3 or 7 site tests, where a trained individual will measure your body fat by measuring different sites of your body. The trained individual will grasp a double fold of skin by pulling subcutaneous fat away from the body, not grabbing any muscle. The individual will then place a caliper on that skinfold and read what the caliper says within 1 to 2 seconds. The trained individual usually does these measurements three times and then plugs the measurements into the Siri equation based on the population specific formula of the client. This test is widely used because it is very fast, inexpensive, and can be done anywhere from your local gym to even your own home. This test has a lot of major flaws even with the pros stated above. The first major flaw is the accuracy of the measurement. The accuracy depends on how skilled the individual doing your test is, how well they pinch each site, the temperature of the room, and the elasticity of the person’s skin. The convenience for the user sounds great when it is so cheap and simply, but a lot of the times it is very uncomfortable for the individual as a person is randomly pinching their fat on sensitive parts of their body. The repeatability of the test measurements also suffers because the test would have to be done by the exact same person and the exact same way every time, which is impossible due to human error. This one ranks higher then BMI because it actually gives your body composition in a percentage.

  1. Hand or Feet BIA (Bioelectrical Impedance)

These hand-held devices or scales have become increasingly more popular in gyms and even devices that one can buy for their own home. BIA devices are very simple to use, the individual just has to enter in their information including height, weight, age, and gender. The individual then either stands on the BIA scale or grips the hand held one. The BIA scales and hand held are very simple, fast, and cost effective. The accuracy of these devices is often questioned because the electric current measuring the body’s resistance is only measured in the portion of the body (arms or legs). This means that people who are not evenly distributed with their muscle and fat between those body parts often have very inaccurate readings. The repeatability of these test measures is good as there is no human error involved, but BIA devices are often affected by the individual’s hydration level, what they eat right before, and if they exercised close to the measurement. The depth of information that this test gives is the same as the skinfold with it just being the percentage of body fat, but the easy convenience for the individual ranks it higher on our list.

  1. Hydrostatic Weighing (Dunk Tank)

Underwater weighing is based off of the Archimedes’ principle, which states that a body that is immersed in fluid is buoyed up by a force equal to the weight of the displaced fluid. This body composition uses the method of water displacement to determine the body composition of the client. This is done by having the client change into a bathing suit, being weighted on land, then placing the client in a swing and submerged in a tank of water. The client then expels all the air from their lungs while remaining completely still. At this point the client’s underwater weight is taken then entered into a formula to find out their body composition. Hydrostatic weighing used to be called the gold standard of body composition because it was the most accurate during that time until new advances came out. Although the accuracy of this measurement is extremely accurate, this method is prone to high technical error. This method is solely dependent on the individual’s ability to remain underwater and expel all of the air out of their lungs. The convenience for the individual is also not very high, as one has to change into a bathing suit and be fully submerged underwater. An individual also may get extreme anxiety from being submerged underwater in a cage without breathing. Although the depth of information gained from this body composition test is the same as the BIA and skinfold and it is not very convenient, the accuracy of this test places it very high on the list because when done right it can represent the gold standard of body composition.

3. BodPod (Air Displacement Plethysmography)

The BodPod is very similar to the dunk tank but instead of using water to measure your body fat, it uses air. The client changes into a tight bathing suit or spandex with a swim cap being required because baggy, loose clothes, or hair could be a false reading of mass. The client is also required not to eat, workout, or drink anything besides water before the test because all of these could affect the mass of the individual which would give a false reading. The trained individual just has to follow the BodPod instructions, which are very easy. The client then steps into the BodPod and sits completely still until the 4-5-minute test is completed. The accuracy of this test is said to have a medium to high accuracy rate, which is almost in par with the dunk tank. The convenience for the user is a lot better than the dunk tank as the user only has to step into a pod, rather than holding their breath under water. The depth of information given from this test is one step above all the rest. The BodPod gives you your body mass, fat mass, fat free mass, % fat, and % fat free mass, while also giving you a rough estimate of your RMR or resting metabolic rate. Resting metabolic rate is the energy required by an animal to stay alive with no activity. This means the number of calories you would burn if you sat in bed all day and did not do anything but breath. This RMR is figured out through a standard equation so it is not 100% accurate, but gives you a good reference point for dieting. The repeatability of this test is great as there is no human error involved but several factors can change the outcome of the results from eating or drinking to close to the test or working out right before. It is recommended that you do everything the exact same as the first test to try and keep the results accurate. What I mean by this is if you drank a ton of water the night before the first test do the exact same for the second test or if you barely ate anything the day before, do the same exact thing for the second test. BodPod ranks higher than the dunk tank even though they have around the same accuracy because it is more convenient for the individual, easier to repeat, and all populations can do it easily.

Karl Leonard, exercise physiologist, Health & Wellness Center measures the lean body mass percentage of Master Sgt. Bartholomew Vasquez on the Bod Pod April 15, 2014 at Joint Base San Antonio-Randolph. (U.S. Air Force photo by Joel Martinez)

  1. DXA or DEXA Scan (Dual Energy X-Ray Absorptiometry)

The DXA machine is a non-invasive procedure that basically scans the entire body. All the client has to do is lay on the DXA table, while it scans their entire body for around 12-15 minutes. The client can wear normal clothes as it is a non-invasive procedure. The accuracy of the test is said to be one of the very best at around a 5% error rate. The DXA scan gives you an incredible depth of information from just one test. The scan tells you your fat mass, visceral adipose tissue, fat location, lean muscle mass, lean muscle location, and bone density. The repeatability of this scan is also impressive as the client does not have to do any major changes before this test like not eating, drinking, or exercising because it is an X-ray rather than measuring some sort of displacement. That means the DXA scan will give an accurate reading basically every time you get measured. The convenience of this test is second to none as all you have to do is lay down without much movement. The only thing not convenient about the DXA is that it is one of the most expensive body composition tests usually right around $100. You may ask why is the DXA scan number two if it has this incredible depth of information, easy convenience, and such an accurate measure? The answer to this is that a new and improved body composition innovation has been created that exceeds the DXA scan in all categories.

  1. SECA mBCA 514

The medical Body Composition Analyzer (mBCA) by SECA is a non-invasive BIA device that has validated precision for calculating body fat mass, fat free mass, total body water, extracellular water, skeletal muscle mass, lean soft tissue and much more. The level of precision is from the incredible features of this device from the standing aid function, which guarantees that the subject is always measured in the right position, in the hand-held electrodes which prevent measurement errors and in the large glass platform which is suitable for weighting patients up to 300 kilograms. Before you say, I thought you said BIA devices were inaccurate that’s why you listed them at number 5? Yes, I did state this for hand, feet, and so called “whole body” BIA devices. The mBCA is known as a DSM-BIA or Direct Segmental Multi-Frequency Bioelectrical Impedance Analysis. The top DSM-BIA on the market is the SECA mBCA 514. First, let’s get into why BIA scales, handhelds, and whole-body BIA’s do not compare to DSM-BIA’s. BIA scales or feet BIA’s only send a current up one of the patient’s legs and down the other. This means that the impedance of the device is only directly measuring the body fat of the patient’s legs than estimating the rest of the patient’s body fat. Handheld BIA devices are doing the same exact thing but instead it is sending one current up one of your arms and down the other. This means it is estimating the body fat of the patient from the chest down. The “Whole Body” BIA devices where electrodes are placed on one side of the patient’s body only measure about half of the body, even though they appear to measure the whole body. This is the case because the impendence is sent through one of the arms then goes down some of the trunk and out your leg. This device is flawed for two reasons, number one, the impedance device is only measuring half of the patient’s body and estimating the rest of the patient’s body fat. Secondly, these whole-body BIA devices treat your body as a single unit meaning that it measures your arms the same way it measures your trunk even though you have different organs and bones in your trunk. Now that we have shown how the most known BIA’s are flawed, I will show you how DSM-BIA differ and are now actually extremely accurate. DSM-BIA or direct segmental multi-frequency bioelectrical impedance analysis is the newest BIA technology and measures the entire body by dividing the body into five segments, where the impedance of each of these five segments is measured independently. The SECA is so accurate that it has been validated against magnetic resonance imaging (MRI) and dual X-ray absorptiometry (DXA), which it is shown to be as accurate or more accurate. (Here is the research study that was conducted that proves these findings ( The SECA has also been validated to the 4-compartment model of body composition. This 4-compartment model or 4C divides the body into fat, water, protein, and mineral and is said to be the most accurate assessment of body fat in the medical community as they use x-ray absorptiometry to obtain the numbers that are plugged into a complex equation. This means that the SECA is as or more accurate than the 4C model. The SECA mBCA 514 is the number one choice for body composition for multiple reasons. First, it only takes 17 seconds to perform as all the client has to do is stand on the platform and grip the sensors, the client can do this in any clothes they prefer, making this the most convenient test. Second, the SECA goes more in-depth than any other test as it measures fat mass, visceral adipose tissue, lean muscle mass, lean muscle mass location on limbs, RMR, hydration levels, and even metabolic syndrome profile or 10-year cardiovascular risk if blood results are entered into the machine, making it the most in-depth test. Additionally, the SECA is as accurate or more accurate than the previous gold standard DEXA scan. Lastly, the SECA is very cheap as it is available at our office for just $60. If you are interested in this incredible body composition analyzer please feel free to call our office, Incredible Health, at (480) 418-3678! You can also visit our website,, for more information! Incredible Health is located at 10595 Tatum Boulevard, E-141, Paradise Valley, AZ 85253.

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