Body Fat - What's the Right Amount?

















We all know that being overweight is a health issue.  How do we know if we are truly overweight for our body type?  Healthy weight is not always reflected by the bathroom scale.  Body composition—the ratio of fat to lean body mass—is a much more accurate and objective measure of health and fitness.  Too much body fat can lead to serious health problems like heart disease, diabetes, high cholesterol, premature aging, cancer, and high blood pressure.  These lifestyle-related diseases comprise the number one cause of death in the United States .  A high fat-to-lean body comp can be an early warning of health problems in the making.

How to Test your Body Composition

There are several ways to measure body composition, some more accurate than others.  The standard bathroom scale is not a great indicator because it measures everything—fat, bone, muscle, and what you just ate and drank.  A better indicator is the Body Mass Index, or BMI.  This is an approximation of body fat based on a height-to-weight ratio.  It works well for people of average build, but is inaccurate if one is extremely muscular; like a body builder; or if one has very little muscle.  For example, Gov. Arnold Schwarzenegger would be considered obese by a standard BMI calculation. 

A more accurate measure is hydrostatic weight measurement, which is the “gold standard” for body composition.  A drawback is that it requires the person to be submerged in a tank of water, and so cannot be easily done.  Another very accurate measure is the skin-fold caliper method, which measures the thickness of fatty tissue by pinching a fold of skin.  Some people shy away from this because it gets a little “personal.” 

A third, and most popular measure is bioelectrical impedance.  This method is based on the fact that there is more water in muscle than in fat; that is, fat is more solid and therefore more resistant to an electrical signal passed through the body.  The more fatty tissue, the more resistance to current; the more muscle, the easier it is for the signal to pass through it.  Don’t worry, the electrical signal used in body fat monitors cannot be felt at all.


What does it mean?

Standards for healthy fat-to-lean ratios (body comp) are given in the following table.  Females are typically healthy with slightly higher body comp than men.  Athletes are generally healthy with lower body comp, while a minimum amount of body fat is essential for health. 

If your body composition falls in the obese category, you could be headed for serious health problems and should seek immediate weight loss and exercise counseling.

PERCENT BODY FAT STANDARDS

Ages

Males

Females

20 – 29

10 – 15%

18 – 22%

30 – 39

12 – 16%

20 – 24%

40 – 49

14 – 18%

21 – 25%

50 +

15 – 19%

22 – 26%

Athletes

5 – 8%

12 – 18%

Essential fat

3%

12%

Obesity

25+%

32+%


Exercise and weight loss

Caution!  Dieting without exercise will increase your body fat percentage.  Why?  Because muscles—composed of about 72% water—break down easier than fat.  Fat tissue is, well, fat.  At only 22% water, fat is more difficult to break down. 

To lose weight while maintaining a healthy body composition, you must include strength training to build and maintain your muscle mass while dieting to reduce the fat.


©2004 Team Safety, Inc. This document may be reproduced and distributed as handouts or training material, so long as the Team Safety, Inc. copyright is visible.