Body fat percentage: What is this and why should you care? Body fat percentage is one of the many important factors that go into our overall state of health and fitness. It is arguably more important, even, than height-weight ratio.
Body fat percentage is why I might weigh much more than someone else who is the identical height and wears a bigger size in clothing than I do. How is this possible? You’ve probably heard the answer before: muscle weighs more than fat. And muscle is more compact (takes up less space) than fat. An athlete with very little body fat most always weighs more (sometimes significantly more) than a same-size someone who never works out.
In the quest for health and fitness, this is the reason why exclusively relying on what the scale says is a mistake… it is also important to know what your total body fat percentage is. Your body fat percentage is an estimate of how much of your body is made up of fat and how much is muscle and other lean body tissues. There are a lot of ways to check out what your body fat percentage is. Let’s touch on some old standards and meet some new kids on the block:
In this old stand-by, a gadget (the skinfold calipers) is used to measure skinfold thickness at various points on your body. This method is easy and can be conveniently done. In fact, this is what is often used by personal trainers at gyms.
Your fat-to-muscle ratio is estimated by pinching your skin with the calipers in order to pull the fat away from your muscle. The results are “plugged in” to a standard formula to calculate your total body fat percentage.
There is a lot of variability in this method, particularly if the person doing the testing is not highly skilled or not very experienced. The results can also be affected by factors including age, as body fat shifts as we grow old gracefully or not, I am sorry to say. The really good news about this method is that it is usually inexpensive (and sometimes free).
Another body fat percentage measurement test is bioelectrical impedance. This is another low-to-no cost test often offered at gyms and health fairs. This is a “zapper” test where you either use a hand-held scale or step onto a scale-like platform that sends a mild and harmless electrical current through your body. The faster the signal from the current, the more muscle you have. The concept behind this: fat blocks the signal to a greater degree than muscle does.
This method is also not entirely foolproof and can be affected by factors including extremes of weight and dehydration.
This is a big fancy name for underwater weighing. This method is a huge pain to both participate in as well as offer to patients, but the payoff is that it is known to be highly accurate. This method is based on the notion that while fat floats, muscle sinks.
To do this test, you sit on a special weight scale in a tank of warm water, blow all the air out of your lungs and bend forward until you are totally underneath the water. After a brief period (5 seconds or so), the machine calculates out your body fat. Sounds fun, right?
The BOD PO This is a relatively new test that utilizes a large fiberglass chamber (the BOD POD) that sort of looks like a big egg (or pod). Research suggests that this method may be just as accurate as underwater weighing. The BOD POD determines how much space you take up within the closed-in chamber which then translates into your body fat percentage.
This test is relatively new and not widely available but it does look promising.
Dual-Energy X-ray Absorptiometry
Dual-Energy X-ray Absorptiometry, otherwise known as DEXA, calculates how much total fat you have but also where the fat is located on your body. In a DEXA, you lie down for about 10 minutes while you get a head-to-toe x-ray. This x-ray measures your body fat, muscle content as well as the overall strength of your bones (your bone mineral density).
This is a great test but is more expensive and typically needs to be recommended, or prescribed, by a physician which again makes it kind of a pain.
And that’s a general rundown on some of the most widely known methods used to check your body fat percentage. Keep in mind that no matter which test you use, it is important to know that this is just one indicator of your overall health. If you need to work on bringing your percentage up or down, you are not alone and you can do it