“I want to lose weight”, five words that can be heard in any gym any day of the year. My concern is people don’t really understand what that’s all about. “Weight” is a vague term if you were to go to the washroom and make a deposit you’ve technically lost weight, if you were to take off a heavy sweater you’d be losing weight… see where I’m going with this? Unfortunately many people know their weight but very few know how many pounds of fat they have or how much their skeleton weighs, granted not too many people would know how much their bone structure tips the scales at it still is part of your body weight.
Let’s dive into what body weight is made of, it includes everything; the weight of your hair, the weight of your organs, the weight of your blood, urine, feces, bones, muscles and fat. From a health stand point the one we care most about would be body fat. Not saying the other items aren’t important but for the sake of convenience body fat is best. Let me illustrate how body fat percentage plays into body weight, if we take two people each 140lbs one of them is 30% body fat and the other is 20% body fat, respectfully they have 42lbs and 28lbs of fat on them. Flip that around through the magic of algebra we get 98lbs and 112lbs of lean body mass. Pretty big difference. To put this into real terms, Amber pictured below is about 110lbs of lean body mass and about 23lbs of body fat. It wouldn’t surprise me if some people would cringe at the idea of being over 130lbs, but looking at Amber and her pictures it’s safe to say she looks healthy, fit and what a lot of people strive towards.
Testing body composition isn’t an easy task, of all the things to test it’s probably the hardest to get accurate and consistent results. Why? Well we can’t dissect people. Since dissection isn’t very good for repeat business we use other means, the ones we use because it’s a good balance between speed and accuracy, are a BIA scale and Skinfold measurements. BIA simply stands for Bioelectrical Impedance Analysis, our electrically inclined friends will figure out quickly that this scale measures the resistance that your body presents to a current. Using the resistance it then uses some mathematical wizardry to spit out a body fat percentage. The big concern with this method is there are a lot of variables that can’t be accounted for. After a workout for example it wouldn’t be able to give an accurate result, while you work out your body will use electrolytes for various functions, these electrolytes will keep your body less resistant to current. Another fun fact if you were to drink a lot of water before doing this test and dilute your electrolytes you would test differently as well. Skinfolds have just as many quirks, for example if you’re out in a warm environment your body will respond by diffusing more blood to your skins surface, this will make skinfolds test higher. You see there really isn’t one great test that covers all variables. Not even the gold standard of an underwater weighing (Hydrostatic weighing), there are a lot of assumed variables.
So if there is no accurate way to test body fat why do we test it? We do other tests along with body fat so that we can compare the results across a few different tests. If for example your body weight came down and body fat came up on BIA scale, but the skinfolds showed a positive movement and say something like circumferences went down as well we might assume that the increase in weight would be due to an increase in lean body mass.
I apologize as I re-read this I notice it reads more like an abstract for a research paper than a blog post. Guess just what happens when you’re ramped up about body composition.