Body Fat Composition and Ideal Body Fat Percent

Body Fat Composition vs Body Weight

The best way to tell whether your diet, fitness or other weight management programs are working for you is to keep track of changes in your body fat composition. Imagine that you weigh 200 lbs on Earth and are 35 percent body fat. On the moon, you would instantly lose about 167 lbs because of lower gravity. However, your body would still be 35 percent fat. The point here is that weight is not the issue. Fat is.

Body Fat Calculations and Types of Fat

Now it gets a little dicey because there is no way to know how much of the different kinds of fat are in your body. Your total consists of brown fat and white fat (both referred to as adipose tissues), and even cell membrane fat.

Brown fat is the new kid on the block for fat loss. At one time it was thought to be present only in infants. Recent research shows its presence in adults. It occurs mostly in the upper chest area and around the neck. The importance of this discovery is that the more brown fat you have, the more able you are to balance other types of fat. Brown fat directs the metabolism of that awful belly fat that most folks want to lose.

You can easily tell when you have abnormal fat made of white adipose tissue because it sticks out somewhere. The usual places are belly, thighs and buttocks, and upper arms.

Ideally, the best fat loss would, therefore, be white fat loss. Indeed, better weight management would include getting your body to make more brown fat and less white fat. So far, scientists have succeeded in getting mice to do this in laboratory research. We do not yet know whether this will work in people. Of course, drug companies are seeking a new miracle drug that will do this for you. No such thing is available at the moment.

Body Fat Recommendations

Keep in mind that measuring total body fat can be misleading, even though it is currently the best indicator of body fat composition. The accuracy of the main three methods of measurement varies.

The most accurate is the submersion test, where your buoyancy in water is used to calculate body fat percentage. The second most accurate method is through impedance devices. These are now available as bathroom scales that read body fat and as handheld devices that use the same principle. In my personal experience, my handheld impedance device measures about 3 percent higher than does the submersion method.

The least accurate method is the caliper method. It varies tremendously because the strength of pinching varies with the examiner.

Regardless of the result that you get, there is a range of body fat composition that is best for optimum health and weight (fat) management. There is no magic number for everyone. Indeed, numbers are always higher for women than for men, and they increase with age.

The general agreement among nutrition researchers offers the following as healthy ranges of body fat percent for women and men in different age groups:


20 to 40 yrs, 21 to 33 percent fat

41 to 60 yrs, 23 to 35 percent fat

61 to 79 yrs, 24 to 36 percent fat


20 to 40 yrs, 8 to 19 percent fat

41 to 60 yrs, 11 to 22 percent fat

61 to 79 yrs, 13 to 25 percent fat

These are the target ranges for good health. It is probably obvious that being above these ranges is the foundation for overweight (i.e., overfat) and obesity. There may be no limit to how high it can go. One of my clients, a woman in her 50s, measured at 48 percent body fat. Wow!

Lower Body Fat Percent Is Not Healthier

What may not be so obvious is that numbers below these health ranges are not necessarily healthier just because they are lower. You need body fat in the right amounts, of the right types, in the right places for optimum health and body image.