In regard to overall health, body weight measured on the scale is not nearly as important as the composition of that weight. Our weight on a scale tells us the combined weight of all our body’s tissues. In contrast, Body Composition reveals the relative proportion of lean mass and fat mass in the body. Lean mass refers to bones, tissues, organs and muscle. Fat mass consist of two types of fat: essential and nonessential fat.
Essential fat is the minimal amount of fat necessary for normal physiological function, typically considered to be between 2-4% for males and 10-12% for females. Dropping below the minimal recommended levels of essential fat negatively affects the delivery of vitamins to the organs, the ability of the reproductive system to function, and overall well-being. Fat above the minimal amount is referred to as nonessential (storage) fat. A certain amount of nonessential fat is considered satisfactory for good health, because it stores energy and protects and insulates internal organs.
A common tool for measuring an individual’s Body Fat Percentage is with a hand-held Body Fat Analyzer, which utilizes bioelectrical impedance analysis. The principle behind this non-invasive technique is that fat contains little water; most of the body’s water is in the lean compartment. Therefore, when an electrical current encounters fat, there is more resistance. By measuring how easily currents move through the body, total body fat can be estimated.*
The Body Fat Percentage resulting from this measurement represents your total fat mass (both essential and non-essential fat) as a percentage of your body weight.
For example, Angie has 32% body fat. If she weighs 150 pounds, she has 48 pounds of total fat mass and 102 pounds of lean body mass.
The Health Standards for Body Composition are provided below. These percentages are slightly higher, or more “relaxed,” than health & fitness industry guidelines.
Normal Borderline High Risk
% Fat, male < 24 24 – 27.9 ≥ 28
% Fat, female < 31 31 - 34.9 ≥ 35
Carrying too much body fat relative to your lean body mass suggests you have a higher risk of developing obesity-related diseases such as diabetes, high blood pressure, and even some cancers. According to the chart above, Angie would be considered “Borderline Risk” and might consider making lifestyle changes to reduce her total body fat. She needs to know that weight loss alone won’t necessarily lead to huge decreases in body fat since weight loss without exercise will also lead to a decrease in lean body mass. To really decrease body fat percentage, she must eat better, perform cardiovascular exercise AND do resistance training to build up her lean mass. Otherwise, with every pound she loses, she will also be losing lean, calorie-burning muscle. Losing muscle is one of the contributing factors involved in weight loss plateaus.
It is important to also understand that even when your weight on the scale stays the same, you can still have changes in your fat mass and lean mass. Changes in body composition take time and a dedicated effort, but the positive impact on health and quality of life is worth the effort. Participation in regular exercise and physical activity along with a healthy balanced diet are the key to reaching and maintaining a healthy body composition.
* A hand-held Bioelectrical impedance device typically has a margin of error of ±3.5%. To reduce controllable variation and improve accuracy, each measurement should be taken at the same time of day, preferably in the morning before eating, caffeine and exercise. Be properly hydrated but consume no more than 8-10 ounces of water 2-3 hours before testing. Please note: Wearers of electronic medical devices and implants (pacemakers, electrocardiograms, etc.) are advised not to use these devices.