What is body fat testing?
Body fat testing checks how much body fat you have. It may be done to find out if you have too much or too little body fat.
The test is one of the ways to measure healthy weight.
People who are trying to become more fit and lose weight sometimes use the test to check for changes in their body fat levels.
How is body fat percentage estimated?
Some common ways to estimate what amount of your weight comes from fat include:
- Skinfold thickness.
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A tool (caliper) is used to measure the thickness of fat at one or more sites on the body. The measurement estimates the amount of fat in your body.
- Bioelectrical impedance.
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A small electrical current is passed through your body to measure the electrical resistance of your body. This helps estimate your body fat percentage.
- Underwater weighing.
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The difference between your weight in and out of the water is used to calculate your body density. This helps estimate your body fat percentage.
- Air displacement plethysmography.
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The difference between the air pressure inside a sealed chamber when you're in it and out of it is used to calculate your body density.
- DXA, or dual-energy X-ray absorptiometry.
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This is a type of X-ray that can tell how much fat tissue you have and where it is.
What do the results of body fat testing mean?
The results of a body fat test give an estimate of how much of your body weight comes from fat.
But body fat percentage is not the best way to measure your risk for weight-related diseases. Your doctor may suggest checking your BMI (body mass index) and your waist size instead. A higher BMI or waist size may mean that your weight is raising your risk for health problems.
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