When it all comes down to losing or gaining weight, most people turn to the scales to determine how much they should lose or gain to have the weight or the shape that they desire.

However, health experts said weight alone is not a clear indicator of good health because it does not distinguish between pounds that come from body fat and those that come from lean body mass or muscle.

Being over fat and overweight is not the same. Overweight simply means an excess of total body weight based on population averages for heights and body frame sizes. On the other hand, obesity is defined as an excess of body fat regardless of weight.

What we have to consider, experts said, in order to determine our fitness, is to know our body fat. Remember that body fat is a percentage of your total weight, so even slender people can have dangerously high levels of body fat. (See

Here are three ways of measuring your body fat:

1. Home Body Fat Scales-- Body fat scales claim to measure body fat quickly and conveniently. These body fat scales use the Bioelectrical Impedance method to measure your body fat percentage. A low-level electrical current is passed through your body and the "impedance", or opposition to the flow of current, is measured.

2. Skin fold Calipers-- Calipers are a tool that looks somewhat like a giant tweezers. These are used to grasp your skin folds at different points on your body and measure the thickness. These measurements are then compared to standard values for persons of your age and gender to give you your estimated body fat.
3. Hydrostatic Weighing—This is just a fancy term for underwater weighing. You sit on a scale inside a tank of water and blow out as much air as you can. You are dunked underwater, where you blow out even more air. Since fat is lighter than water, the more fat you have, the more you will float. The scale measures underwater weight to figure out body density. The margin of error is around 2-3%, but the accuracy depends on the amount of air you expel. You have to blow it ALL out or it will not be as accurate. This is a difficult way to measure body fat since it can be uncomfortable and even scary to be dunked underwater with no air in the old lungs.