By Judy Torel<\/p>\n
In the past decade obesity has become epidemic in our country—not only for adults, but children as well. Most people use a scale weight to monitor body fat, but this measurement does not accurately depict body fat levels. Many people may be within a healthy weight according to charts, yet have an unhealthy percentage of body fat relative to muscle, bone, organs and water levels. How do you know if you are over fat if the scale does not directly measure fat levels?<\/p>\n
Calculation equations
\nThe easiest, most accessible way to assess if you are over fat is to use calculation equations combined with a few basic girth measurements. The two commonly used equations that are simple to calculate are Body Mass Index (BMI) and the Hip to Waist Ratio.<\/p>\n
BMI determines a ratio of body weight to height and then provides an interpretation as to whether your body weight is too high relative to your height. The assumption is that people with a higher ratio have higher, unhealthy levels of body fat. The formula for BMI is:
\nBMI = weight in pounds x 703
\n(height in inches) x (height in inches)<\/p>\n
Healthy range of BMI is 18.5-24.9. If your BMI is between 25 to 29.9, you are considered overweight. A BMI over 30 is considered obese.
\nThere is one problem with the BMI measurement. Athletes, or individuals with higher muscle mass relative to height will find their BMI computation may place them in the overweight or obese category. The reason is that this equation assumes the higher weight ratio is due to higher body fat levels, but this is not always the case.<\/p>\n
The second calculation equation that is easily performed is the waist to hip ratio, a comparison of the waist size relative to hip size. The higher the ratio the more abdominal fat a person is storing and the higher the risk of illness. Abdominal fat is linked with many chronic diseases and is particularly dangerous to health.<\/p>\n
To determine waist to hip ratio, use a measuring tape and measure the smallest part of your torso between your lowest rib and your navel. Then measure the widest section of your buttocks keeping your feet together. (It is best to have a second person take these measurements for increased accuracy).<\/p>\n
Waist to Hip Ratio = waist measurement
\nHip measurement
\nA ratio of >= .95 for women and > = .86 for men is considered too high.<\/p>\n
Both of these equations are easy to perform and can be used in combination with the scale weight to assess whether you are in a category of fatness that is considered overweight or obese. These equations do not, however, determine the actual amount of fat on
\nthe body.<\/p>\n
Methods for measuring body fat
\nSome people want to go beyond knowing if they fall into a category of overfat\/obesity and want to know an actual measurement of a percentage of body fat. This can be helpful if you are beginning a program to lose fat and want to track your success. The scale does not accurately determine fat loss. Someone who is losing weight on the scale may actually be under eating protein, not exercising and be losing muscle weight more than fat. It is also very common for people to show a decrease on the scale that is mostly water weight and not fat. Direct measurements of body fat can help provide valuable information so that the weight being lost is definitely fat.<\/p>\n
Bioelectrical Impedance has fast become a method the average person can use to measure fat percent and pounds. Bio-Impedance measures electrical signals as they pass through fat, muscle and water in the body. Laboratory research has determined the exact speeds of which an electrical current will pass through these various tissues of the body. By measuring the speed of the electrical impulse between two electrodes and plugging these speeds into complex scientific equations, body fat can be determined.<\/p>\n
Many scales are available in retail centers that measure scale weight and through bio-impedance, they also measure body fat levels. Having both measurements allows a person to not only assess weight loss success, but can also insure that the weight is coming from unhealthy levels of body fat.<\/p>\n
The problem with this measurement is that hydration levels can dramatically affect the accuracy of the fat reading. Your measurement can be inaccurate if you exercise and sweat before the measurement or if you’re a woman and measure your fat level at a different point in your menstrual cycle. In these circumstances and others, this measurement may not always be accurate.<\/p>\n
The use of skin fold calipers, also known as anthropometry measurement, is potentially the most accurate and assessable measurement of body fat for the average person. This method is based on the assumption that fat levels at specific sites reflect a constant proportion of fat through out the body. These measurements are often performed in fitness centers and medical settings. Using hand-held calipers that exert a standard pressure, various sites on the body are measured (typically 3-9 sites). These measurements are then applied to standardized equations and a body fat percentage is determined based on the sum of the measurements. To date there are over 3,000 equations for using this method to determine body fat. There are different equations for children and individuals of different ethnicities. Different populations of people have different fat distribution patterns, which is why various equations have been created.<\/p>\n
Although this method has been shown to be a valuable and credible method, its accuracy is sometimes subjective. The precision of the clinician taking the measurements and the quality of the calipers makes a difference in the accuracy of the measurement. Home use calipers are less accurate then those used by an accredited technician. This method is also more difficult to perform on very obese individuals when the skin folds of fat are larger than the calipers can accommodate.<\/p>\n
Other measures
\nWith the development of science and technology, we now have several laboratory methods for measuring body fat. Hydrodensity weighing requires an individual to be submerged in a special designed water tank and compares weight on land to weight under water. The densities of muscle and bone are higher than water and the density of fat is lower than water. Through calculations, fat pounds can be determined using this method. Other methods including Dual Energy X-Ray Absorptiometry (DEXA), Near Infrared Interactance (NIR), Magnetic Resonance Imaging (MRI), Total Body Electrical Conductivity (TOBEC), and Computed Tomography (CT) use various energy forces to determine body fat percentages. The problem with these methods is that they are expensive and inaccessible to most people.<\/p>\n
Final thoughts
\nThe scale weight does not accurately determine body fat levels or fat loss during a weight loss program. Using simple equations and measurements, you can determine if you are in a category of over fat or obese. Finding a qualified technician can help you to determine the percentage and pounds of fat on your body and provide you with a tracking method to ensure you are reducing fat if you are on a weight loss program.<\/p>\n
Due to the rising levels of obesity in our children, I strongly suggest that a body fat measurement be part of the evaluation process to determine the health of a child.<\/p>\n