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Know your Body Fat Percentage
Your body weight includes not just the fat that you want to get rid of...
The term Lean Body Mass (LBM) represents all of you except your fat. When you step on a bathroom scale and look down, you see a number. In everyday terms, this number represents your total body weight. Unfortunately, your scale does not differentiate between lean body mass and body fat. Knowing your body fat percentage (BF %) will tell you exactly how much of your total weight is lean body mass and how much is fat. For example, if a 150 pound person has a body fat percentage of 20 percent, then this means they are carrying 30 pounds of fat (150 lbs x 0.20 = 30 lbs). Since whatever isn't fat is muscle mass, then they have 120 pounds of LBM (150 lbs - 30 lbs = 120 lbs). You should know that whenever you lose weight, you don't just lose body fat exclusively. Some of that weight loss will stem from your lean body mass. In general, the faster and the greater the rate of weight loss weekly, the more muscle mass you stand to lose which is why it's important to stick to
healthy weight loss program guidelines.
First, consider two people with identical weight and body fat percentages. Suppose they both want to lose 30 pounds. The first person adopts a slower but steady rate of fat loss and includes weight training to minimize any lean muscle loss. The second person just wants rapid weight loss through excessive calorie restriction. Technically, our second candidate will lose more muscle mass than candidate number one. If they both lose the same amount of body weight, their body fat percentages will differ at the end of their weight loss trial. True, it will take candidate number one longer to reach the same weight loss, but her body composition will improve more than candidate number two. Ironically, the scale will reflect the same weight loss. Just looking at the number on a scale can be misleading. Judging by the bathroom scale alone, neither will know the 'quality' of their progress-- unless they measure their body fat percentage. Losing 30 pounds if more of it is body fat and less of it is muscle mass, is not the same as losing 30 pounds if less of it is body fat and more of it is muscle mass. The only way to tell what's really going on is to measure your percent body fat. Knowing your body fat percentage is absolutely fundamental in getting a clear picture of where you stand, and perhaps more importantly, in gauging the progress you make over time.
Let's try another example to illustrate what we mean. Let's say you're a 45 year old male who weighs 200 pounds. You remember weighing 150 pounds in your youth and feeling good at that weight so you figure you want to lose about 50 pounds. Does this sound like a reasonable goal to you? If you don't know your body fat percentage you may very well go for it. However, you decide instead to drop by your health club and have your body fat percentage measured. Suppose your personal trainer tells you your body fat percentage is 23 percent. At 200 pounds, 23 percent of your weight or 46 pounds is body fat (i.e., 200 lbs x 0.23 = 46). Recall that whatever isn't fat is considered your lean body mass. Therefore, if you weigh 200 pounds and 46 pounds are fat, then the rest of it, or 154 pounds is your LBM (i.e., 200 lbs - 46 lbs = 154 lbs). This means that at 23 percent body fat, you have 46 pounds of fat and 154 pounds of muscle. The first thing that should strike you is that you don’t have 50 pounds of fat to lose. You only have 46 pounds. Not only that, but it's not possible to lose all of your body fat. Some of your body fat is considered essential. In fact, it's called... "essential body fat." For example, fat protects vital organs such as your heart, liver, spleen, kidneys, brain, and spinal cord against trauma. In men, 2 to 3 percent and for women, 8 to 12 percent is considered essential body fat. Losing this fat would compromise physiological functioning. Women naturally have more body fat than men because it is believed that the female body requires this fat for childbearing and hormonal functions. ...So we see that setting a weight loss goal of 50 pounds might not be such a great goal after all. Instead, you should be setting a body fat percentage goal. Here's how to do that... Use a formula such as this one to calculate an ideal or desired body weight:
At a current 23 percent body fat and a desired body fat goal of 15 percent, your ideal body weight becomes:
Therefore, the amount of body fat you need to lose is 18.82 pounds-- only about 10 percent of total body weight, i.e., 200 lbs less your ideal weight of 181.18 pounds. Indeed, a 5 to 10 percent reduction in weight is often a reasonable, conservative initial goal. Additionally, it's important to note that your ideal weight or healthy weight range does not need to be achieved to realize health benefits. Even modest reductions in body weight can significantly improve your health. In fact, research indicates that as little as 5 to 10 percent weight reduction may decrease your blood pressure, blood lipids, and reduce factors related to the onset of Type II diabetes. So, with less than 20 pounds to lose and using an appropriate weekly weight loss rate of 1 to 2 pounds, it should therefore take you approximately 10 to 20 weeks to meet your body fat reduction goals. Note that from a mathematical perspective this is all nice and tidy. Bear in mind that this technique is simply a tool to help you approximate your goals and remember that in real life you will likely be losing a little bit of lean body mass despite your best efforts to sustain slow and steady fat loss. Now that you know what body fat percentage is and why it's important in distinguishing between body weight and body fat, and in helping you set clearer goals-- you might be asking yourself... How do I tell what my body fat percentage is? What methods are used to calculate body fat?
Jump from Body Fat Percentage back to Ideal Weight Section
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