Overweight and overfat do not always mean the same thing. Some people are quite muscular and weigh more than the average for their age and height. However, their body composition, the amount of fat versus lean body mass (muscle, bone, organs and tissue), is within a desirable range. This is true for many athletes. Others weigh an average amount yet carry around too much fat. In our society, however, overweight often implies overfat because excess weight is commonly distributed as excess fat. The addition of exercise to a weight control program helps control both body weight and body fat levels.
A certain amount of body fat is necessary for everyone. Experts say that percent body fat for women should be about 20 percent, 15 percent for men. Women with more than 30 percent fat and men with more than 25 percent fat are considered obese.
How much of your weight is fat can be assessed by a variety of methods including underwater (hydrostatic) weighing, skin fold thickness measurements and circumference measurements. Each requires a specially trained person to administer the test and perform the correct calculations. From the numbers obtained, a body fat percentage is determined. Assessing body composition has an advantage over the standard height-weight tables because it can help distinguish between "overweight" and "overfat." An easy self-test you can do is to pinch the thickness of the fat folds at your waist and abdomen. If you can pinch an inch or more of fat (make sure no muscle is included) chances are you have too much body fat. People who exercise appropriately increase lean body mass while decreasing their overall fat level. Depending on the amount of fat loss, this can result in a loss of inches without a loss of weight, since muscle weighs more than fat. However, with the proper combination of diet and exercise, both body fat and overall weight can be reduced.