5 Ways To Measure Body Fat

Weight management is an integral part of maintaining good health. If you are aiming to lose weight, build muscle mass or exercise more regularly to improve your physical fitness then you will be interested in the body composition changes that are occurring as a result of your hard work. Body mass index (BMI) is a universal measurement used to assess health and class individuals according to their weight to height ratio. Unfortunately, BMI does not take body composition into account and so produces inaccurate readings for bodybuilders, large athletic builds and also slight athletic builds such as gymnasts and pole vault athletes.

Body fat measuring is a great way to keep track of progress and provide you with a more accurate indication of body composition changes. If you want to keep track of overall weight loss you can combine any of the measurements below with the use of scales to get an accurate measure of both fat loss and weight loss. From inexpensive and simple to expensive and elaborate there is something to suit everyone from the fitness enthusiast to elite athlete.

Body fat ranges (%) for men and women:

Classification

Women

Men

Essential Fat

10-13%

2-5%

Elite Athlete

14-20%

6-13%

General Fitness

21-24%

14-17%

Acceptable

25-31%

18-24%

Unhealthy/ Too High

32%+

25%+

 Skinfold Measurements

Skinfold measurements are taken by pinching the skin and subcutaneous fat layer with body fat calipers and measuring the thickness of the fold. A caliper is a device which measures this thickness of subcutaneous fat by clamping the skinfold between its two arms (like a vice but much less scary) alongside a ruler which measures the fold in mm. Skinfold measurements are taken at key locations around the body to estimate the amount of fat on the entire body and the total percentage of body fat.

The four commonly used sites for this type of fat measurement are: bicep, tricep, subscapular (below shoulder blade) and iliac crest (along a diagonal plane above the hip on the lower abdomen).

To measure the sight properly you should hold the fold with your less dominant hand and use the caliper with your dominant (writing) hand. Continue to hold the fold with your hand while using the caliper to measure as this will prevent the fold from slipping or the caliper from squeezing tighter and inaccurately measuring the thickness. You will need someone else to take the readings of your own body so ensure that you choose someone who is going to measure you properly and not be ‘kind’ and only pinch a small amount of skin.

Once you have taken all four readings, add them together and use the total to estimate your total body fat.

There are varying formulas to calculate your results depending on the body sites and number of body sites that you take your measurements from. Skinfold measurements can predict total body fat at up to 98% accuracy if conducted properly so it is best to consult a professional to get the best results.

Anthropometric Measuring

Anthropometric measuring is a non-invasive way to estimate total body fat by analysing specific dimensions of the body. The most cost-effective and simple way to do this is by using a measuring tape. While it is not particularly accurate and the girth of body sites is not directly related to body fat, it does give a better insight into body dimensions and helps you to keep track of the progress that you are making. The accuracy leaves a lot to be desired as individuals with particular body types may carry more girth in their midsection without carrying extra body fat. I would not recommend this as a way to measure body fat but it is a helpful addition in combination with scales and body fat measurements.

Hydrostatic Weighing

Hydrostatic weighing involves being completely submerged in water. This process measures body density and body fat percentage is then calculated from this using either the Siri or Brozek equations. Before being submerged in water, dry weight is recorded and residual volume is either calculated or estimated depending on the equipment available. The individual then has to expel air from the lungs and lower themselves under the water until they are sitting on a specialised seat. Remaining as motionless as possible while submerged is important in order to gain the most accurate reading possible. Protocols like this are usually repeated several times in order to get the most dependable measure possible.

This process is based on Archimedes Principle of body displacement which is a law of physics stating that the upward buoyant force exerted on an object immersed in fluid is equal to the weight of fluid displaced by the object. This method is a relatively accurate and expensive way to measure body fat. Although it was once considered the gold standard of body fat estimation, there are now more advanced methods available.

DEXA Scan

Among several methods for studying human body composition, dual-energy X-ray absorptiometry (DEXA) has emerged as one of the most commonly used clinical methods. Typically the energy source produces photons at two different energy levels, 40 and 70 keV, which pass through tissues and attenuate at rates related to elemental composition. Bone is rich in highly attenuating minerals such as calcium and phosphorous and is easily distinguished from soft tissues. The unique elemental profiles of bone, fat, and lean muscle tissue allow for visualisation and separate analysis of each tissue type. Most currently marketed DEXA instruments use standardized calibrations, have quick scans (5–20 mins) and use standard software for analysis. The ability to study body composition in the whole body and individual body segments is helpful for determining body fat distribution and regional bone mineral density.

Bioelectrical Impedance

Bioelectrical impedance involves running a light electrical current through the body to determine body density. The current travels at varying rates depending on tissue structure and so the total time which elapses before the current is returned to the device gives an estimation of body composition. The current passes rapidly through lean mass but fat mass causes resistance to the signal which slows the rate of the current.

An individual’s height, weight and gender are recorded prior to the bioelectrical impedance test. The great thing about bioelectrical impedance measuring is that it is now easily obtained by the general public. You can find this technology in scales and handheld devices which start at approximately £20. The reliability of the results can be questionable as the amount of water in your body at the time of testing can drastically alter the readings. The body is predominantly composed of water with ions, through which an electric current can flow. If you alter your hydration status it will change the reading. High levels of water are likely to underestimate body fat and low levels are likely to overestimate.

References:

Dehghan M, Merchant AT, Is Bioelectrical Impedance Accurate For Use In Large Epidemiological Studies? Nutrition Journal, 2008, 26(7).

Demerath EW, Guo SS, Chumlea WC, Towne B, Roche AF, Siervogal RM, Comparison of Percent Body Fat Estimates Using Air Displacement Plethysmography and Hydrodensitometry in Adults and Children, International Journal of Obesity and Related Metabolic Disorders, 2002, 26(3):389-97.

Biaggi RR, Vollman MW, Nies MA, Brener CE, Flakoll PJ, Levenhagen  DK, Sun M, Karabulut Z, Chen KY, Comparison of Air-Displacement Plethysmography with Hydrostatic Weighing and Bioelectrical Impedance Analysis for the Assessment of Body Composition in Healthy Adults, American Society for Clinical Nutrition, 1999, 69(5):898-903.

Garcia AL, Wagner K, Hothorn T, Koebnick C, Zunft HJF, Trippo U, Improved Prediction of Body Fat by Measuring Skinfold Thickness, Circumferences and Bone Breadths, Obesity Research, 2012, 13(3):626-34.

About the Author

Job Role Sports Nutritionist and Social Media Coordinator Qualifications Bsc Sport and Exercise Science Steph has a competitive athletic background which spans 19 years. As a child she performed with the English Youth Ballet and had performed on the West End stage by the age of 10. Her enthusiasm for sport and fitness continued to grow as she did, encouraging her to learn more about nutrition and training. She began using her knowledge and personal experience to help others when she began coaching at the age of 16. From here, she went on to study Sport and Exercise Science at the University of Essex during which time she also received the Most Promising Newcomer Award from her University to mark her outstanding contribution to sport. During her first year of study she was introduced to partner stunt acrobatics and artistic gymnastics. After one year of dedicating herself to a lifestyle revolving around her sport, she was training with the best team in the UK who are currently ranked fifth in the world. Steph has worked in both the private and public sector coaching children and adults from grassroot to elite level as well as providing them with cutting edge advice on how to reach their goals. Steph has received awards for her choreography and has competed nationally and internationally meaning that she can back up her scientific knowledge with a wealth of experience. As our resident Sports Nutritionist, Steph is here to provide the most current and evidence based fitness, health and nutrition information to help you reach your health and fitness goals.
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