Most body fat measurements tell you what percentage of your weight is made up of fat tissue. When you know this percentage and your total weight, you can easily figure the number of pounds you carry in fat. It's important to keep your body fat percentage within a healthy range, because as it goes up, so does your risk of developing chronic health problems. If you're a man with more than 20 percent fat or a woman with more than 30 percent, you're at an increased risk of metabolic syndrome, heart disease and type 2 diabetes.
Your Body's Composition
Your body is composed of lean tissue, which consists of muscle, bone, connective tissue and internal organs, and fat tissue, comprising both the essential fat that exists within the bone marrow, internal organs and central nervous system, as well as storage fat that lies just under the skin and deep in the belly. Essential fat is necessary to maintaining proper bodily functions.
In men, essential fat averages 3 percent, while in women it's more like 13 percent. Women carry a higher amount of essential fat to sustain another life during pregnancy and childbirth. Storage fat is often thought of as excessive, but some helps to provide energy, regulate your body temperature, pad internal organs and optimize vitamin absorption. Although health organizations differ in their recommendations, between 15 and 20 percent is a healthy, average rate of body fat for men and 20 to 25 percent for women. Athletes may have lower body fat percentages because of their activity levels and the need to be lighter for competition. A lower body fat percentage also makes your body appear more defined and muscular.
Measuring Body Fat
Many methods of measuring body fat exist, some more precise than others. Some scales use bioelectrical impedance, in which the scale sends a light electrical current through your bare feet to determine the amount of lean tissue compared to fat. These body fat scales can give widely varying readings, depending on your level of hydration and their quality. More accurate models that send the current through your hands as well as your feet are available in some health clubs and doctor's offices.
A skinfold test performed using body fat calipers is more accurate. A trained assessor measures at several places on your body, such as your waist and upper arms. The results are plugged into an equation to estimate your body's fat level. The accuracy of the test is subject to the assessor's experience and the quality of the calipers. Skinfold analysis also assumes that all people distribute body fat in the same areas, which isn't always true.
The most accurate assessments of body fat must be performed in a clinical setting and can carry a high price tag. DEXA X-ray scans, primarily designed to measure bone density, and hydrostatic, or underwater, weighing are two methods considered to be gold standards in body fat assessment.
Figuring Body Fat Pounds
Once you know your body fat percentage, figure out how many pounds of fat you carry by multiplying your weight by the percentage of fat. For example, if you're a 200-pound man with 15 percent body fat, simply multiply 0.15 x 200, which results in 30, the number of fat pounds you carry. In another example, a 140-pound woman with a body fat percentage of 25 can multiple her weight -- 140 -- by the decimal representing percent -- 0.25 -- to get 35 pounds.
Subtract fat pounds from your weight to estimate your amount of lean tissue. The 200-pound man with 15 percent fat thus carries 170 pounds of lean tissue, and the 140-pound woman with 25 percent fat carries 105 pounds of lean tissue.
Reducing Body Fat
When you lose weight, ideally, you aim to lose body fat and not lean tissue. If you lose weight with a drastic calorie deficit or without exercise, you're also likely to drop muscle mass.
Aim for a weight-loss plan that has a deficit of just 500 to 1,000 calories per day, for a loss of about 1 to 2 pounds per week. Expect to safely drop about 1 percent body fat per month. If you're already quite lean, you can continue to drop body fat, but aim for a slower rate of loss, such as 1/2 pound per week. You might desire the appearance and bragging rights associated with a super low body-fat level, but dropping below 8 percent for men and 13 percent for women affords no additional health benefit.
To lose fat, stick to lean proteins, whole grains, vegetables and fruits at most meals. Exercise is a must and should include both cardio and weight training. The cardio helps you use up fat for energy, and weight-training retains and builds lean muscle.