When it comes to our bodies we have various forms of measurements to determine our composition. We have our BMI, Skin Calipers, DEXA scans, and Bioelectrical Impedance as methods of measurement. Big question is: which method is best? We will discuss and determine which method of measurement may be right for you.
Most of us have heard of this phrase and what it stands for, Body Mass Index. This measurement is used to determine whether an individual is underweight, normal weight, or overweight. This form of measurement is not a direct calculation of an individual’s body fat percentage.
BMI is based on an individual’s weight and height. If a person has a BMI in a at risk zone, meaning overweight, they may develop increasing health risks. This being said, the interpretation for BMI is up for discussion based on factors your BMI does not consider. These include: age, sex, ethnicity, and muscle mass.
Due to BMI not measuring body fat directly, it is not always the best indicator of body composition. Take for example a olympic weightlifter who carries a lot of muscle mass. Based off of their height and weight, they more than likely will register in the “overweight” category. This placement of individuals is not uncommon, and therefore may not always be the best means of body measurement.
One of the most widely used and easiest methods of determining your body fat measurement is through skinfold assessments. This is done by measuring about 3 different sites. The word, “sites” is referring to a different part of the body for measurement. For example, the sites that are typically taken are your tricep, subscapular, stomach, thigh, and chest. What these sites do is provide a numerical output to plug into the formula to determine an individual’s overall body fat percentage. The technician who is performing the skin caliper test will “pinch” an area of the skin, which is used to measure the thickness of the skin fold. From here, the technicians can compute your body fat percentage. One of the best parts of the skin caliper tests is that it is relatively inexpensive to do, comparative to other measurement methods. Another benefit of the skin caliper test is that it is not time intensive. On the other hand, there is a good margin of error that can occur considering you are measuring from multiple sites. Ensuring you are taking quality measurements takes a considerable amount of practice. If a technician is new, this also can increase the margin of error. With that being said, a study conducted by the University of Las Vegas measuring the accuracy of skin caliper measurements, found the the margin of error between consecutive tests proved to be not statistically significant. An additional issue that can arise with skin caliper tests would be individuals vary on areas of fat distribution. Not all individuals carry fat in the same manner, example: pear shaped individuals vs apple shaped. This can throw off the calculation.
Also referred to as bone density scan, a DEXA Scan (dual-energy x-ray absorptiometry) is similar to an x-ray. This type of scan is one of the most advanced ways to get a complete body composition as well as measuring an individual’s bone density. It is considered the Gold standard for measuring bone mineral density as well deducing fat mass from muscle mass. The way a DEXA scan works is through the emission of two different light beams. A higher energy beam is absorbed by the bone and soft tissue. The low energy beam is only absorbed by your body’s soft, or muscle and fat, tissue. These different emissions help to compute your body’s bone mineral density and body composition. DEXA scans are excellent sources of information due to their ability to break down fat and muscle composition in specific areas. These scans can break down limb per limb to ensure you are receiving an accurate estimate of both fat mass and muscle mass. Another great advantage of the DEXA scans is getting a clear answer as to muscle mass development in specific regions. Especially in athletes, you can determine whether your body has muscular imbalances.
DEXA scans may be considered the Gold Standard for body composition, but they still have a few issues surrounding them. The availability of DEXA scans are limited. Unlike skin calipers, these scans are not at your disposal. Most DEXA scans must be approved through a medical professional.
The name may sound a tad intimidating, but far from! Bioelectrical Impedance is a hand held machine that will send an electrical current through the body. You don’t feel a thing though! What this is measuring is how long it takes for the signal to return back to the device. This device helps to determine the body’s fat percentage based off the electrical impedance. So what would determine a quick signal vs a delayed? Your body’s fat-free body mass (muscles, water, etc.) vs. fat mass. The fat-free mass will conduct the signal much faster than fat mass. Benefits of Body Impedance include cost and the availability to own one of these machines in your own home. Also, the ease of use in high. All that is typically required is the push of a button! In recent years, bioelectrical impedance has proved to increase it’s accuracy rates. According to the Department of Health and Human Performance, studies produced on home models of Bioelectric Impedance Machines proved to all have statistical significant results showing that their accuracy was reliable.
What This All Means
Depending upon the reason for determining your body composition can help you decide which level of measurement you may need. To receive the most precise results, the DEXA scan may be the fit for you. If you just need a quick check on your body’s overall health, maybe doing a simple BMI test or Skin Caliper exam can help! Whichever test you may choose, keep in mind that all tests have their pros and cons. Always consult with a physician upon your findings!