How to Measure Body Fat
Before you learn how to measure body fat, you may be pleasantly surprised to find that there is a fairly wide range of body fat that a person can have and still be considered healthy. In general, body fat over 25 percent in men and 32 percent in women increases health risk.
So how do you estimate your body fat? There are a few ways, and some are more practical and less expensive than others. Waist circumference, which assesses abdominal fat, is more predictive of the risk of coronary heart disease than boday mass index. In addition, a waist measuring more than 35 inches for women and 40 inches for men raises the risk of other obesity-related conditions, such as type 2 diabetes and high blood pressure, and it is one of the factors used to diagnose metabolic syndrome.
Similarly, the INTERHEART study found that abdominal obesity as measured using a ratio of fat distribution (determined by dividing your waist measurement by your hip measurement) over 1.0 for men and 0.8 for women increased the risk of heart attack by up to 2.5 times.
Using a caliper, a skinfold test estimates body fat by taking a pinch of skin in the abdominal area, upper arm, and back to measure the thickness; this test, however, may not provide an accurate measurement in obese individuals.
Another test, bioelectrical impedance analysis, measures body fat by evaluating how well a tiny electric current is conducted through the body. Muscle and water conduct electricity, and the current passes through them easily. However, fat does not conduct electricity, and the current meets resistance. Because conductivity is sensitive to water, changes in hydration can produce different results in the measurement.
Dual energy X-ray absorptiometry is an accurate method to measure body composition using two low-dose X-rays to determine total body fat, fat distribution, and bone mass and density. Underwater weighing -- which calculates dense muscle tissue and fat tissue -- and air displacement plethysmography are two more methods of measuring body composition.
If you find that you have a little too much body fat, the American Heart Association has recommended solutions. Learn how to change your diet and your lifestyle on the next page.
For more information about losing weight, see:
- Coronary Heart Disease: This condition is the culmination of years of plaque buildup in the arteries. Find out how to prevent it.
- Diabetes: This disease, which affects blood sugar levels, affects more than 20 million Americans. Start here to understand diabetes.
- Benefits of Exercise: Regular physical activity can help you with everything from keeping weight off to preventing heart disease. Find out how to improve and extend your life through exercise.