Keeping your weight and body fat at healthy levels lowers your risk for heart disease, Type 2 diabetes and some types of cancer. You can't rely on your weight alone to determine whether you are healthy, since two people who are the same weight could have very different levels of body fat. Although getting an exact measurement of your body fat can be difficult, an estimate can help you tell whether you are on the right track.
Body Fat Percentage Categories
For women, a body fat level of 20 percent falls into the athlete category, so this is a healthy body fat level. Women need at least 11 to 13 percent body fat; otherwise, their periods will stop and it's likely they will be unable to get pregnant. Female athletes often have body fat levels between 14 and 20 percent. If your body fat is between 21 and 24 percent, you are in the fitness category. The average amount of body fat for women is between 25 and 31 percent. A body fat level of 32 percent and above puts you in the obese category.
Measuring Body Fat
Getting an accurate body fat measurement can be difficult and expensive. According to MayoClinic.com, the most accurate measurements come from underwater weighing; dual energy X-ray absorptiometry, a special X-ray exam that gives detailed information about fat, muscle and bones; and air displacement plethysmography, which involves sitting in an egg-shaped chamber that measures your body density and weight. One of the more common and inexpensive ways to measure body fat is by using skinfold measurements, but this has a much larger margin of error since it can be off by as much as 3.5 percent.
Body Mass Index
Due to the cost and difficulty of getting accurate body fat measurements, many doctors rely mainly on body mass index, or BMI, rather than body fat measurements. BMI estimates whether you have excess weight by dividing your weight in kilograms by the square of your height in meters. A BMI between 18.5 and 24.9 is considered normal, while anything above this is overweight and anything below this is underweight. Most recent studies rely on the risks and benefits of having a certain BMI, rather than a certain amount of body fat.
No matter how you estimate your body fat, remember that this is only an estimate, and no measurements are 100 percent accurate. BMI measurements tend to overestimate body fat in people who are very muscular, for example, and they are mainly used as a screening tool to see whether further testing is necessary. Skin caliper measurements depend on measuring the right locations, and they should be done by the same person each time so they are comparable. If you use the same method for estimating your body fat every time, you can get a good idea of whether your body fat is increasing or decreasing and whether it is around the healthy level even if the measurement isn't exact.
- American Council on Exercise: What Are the Guidelines for Percentage of Body Fat Loss?
- Centers for Disease Control and Prevention: Body Mass Index: Considerations for Practitioners
- MayoClinic.com: Body Fat Analyzers: How Accurate Are They?
- American Council on Exercise: Calculate Your Percent Body Fat
- Weight-control Information Network: Do You Know the Health Risks of Being Overweight?
Based in Massachusetts, Jessica Bruso has been writing since 2008. She holds a master of science degree in food policy and applied nutrition and a bachelor of arts degree in international relations, both from Tufts University.