Measuring Fat and Weight Loss: More Than Stepping on the Scale

In light of the constant stream of fad diets and the increasing concern for obesity, researchers are constantly looking for the best measure of weight loss. Most people judge their weight loss by checking the scale or noting that their clothes fit looser. While these are both good methods, weight loss is not evenly distributed throughout the body. Therefore, if your clothes do not fit more loosely, it is still possible that you may have lost weight. In addition, if you have increased physical activity as part of your weight loss plan, you may have increased muscle, which may cause your clothes to fit tighter or cause the number on your scale to tip higher. An increase in muscle mass is a good sign, because it may indicate that you have lost some fat. As a result, there are numerous ways to help measure weight loss.

BMI

Perhaps the most common indicator of a healthy weight is body mass index (BMI). Most researchers and health professionals use the BMI as a way to determine if your weight is healthy for your age and gender. To calculate BMI, use the following formula:

For children, BMI percentiles are used to indicate the category into which a child falls:
 

• Underweight (less than 5th percentile)
• Healthy weight (5th %ile to <85th %ile)
• Overweight (>85th %-ile to <95th %ile)
• Obese (>95th %ile)

For adults, your calculated BMI (based on your height and weight) number determines your weight status. BMI is a good method for screening the general population, but can be inaccurate due to its inability to consider the weight of muscle. Therefore, using BMI as an indicator, along with another measurement, may be better at predicting health problems - such as heart disease - associated with weight status.

Waist Circumference

One of those better options is waist circumference. This inexpensive and easy method for measuring body fatness helps to determine if your weight status affects your health. According to the National Heart Lung and Blood Institute (NHLBI), waist circumference is associated with determining your risk for diabetes, high blood pressure, and cardiovascular diseases because fat found around the waist has been linked to increased health problems. To determine your waist circumference, wrap a tape measure around your waist sitting at the top of your hip bones. (If the hip bone is difficult to find, use your belly button as a guide.)

Make sure the tape measure is not tight around the waist, but is snug and that you are fully relaxed and breathe out. Women with a waist circumference greater than 35 inches or men with a measurement greater than 40 inches have increased health risks, such as diabetes and heart disease.

Changes in waist circumference measurements, along with BMI, are good indicators of whether or not you have an increase in fatness, even if your BMI stayed the same. Waist circumference is more useful to those who have a BMI considered in the normal and overweight category (BMI between 18.5 - 34.9). If BMI is greater than 35 (obese), the waist circumference has not shown to be any more useful in predicting other health risks.

Waist-to-Hip Ratio

Another form of measurement is the waist-to-hip ratio, which is calculated by dividing your waist circumference by your hip circumference. Essentially, this is a calculation of the smallest section of your waist (around the belly button) and the largest section of your hip (around the buttocks).

According to the CDC and the National Institute of Diabetes, Digestive and Kidney Diseases (NIDDK), women with a waist-to-hip ratio of less than 0.8 and men with a ratio of less than .9 are considered healthy. Anything above that could correlate health risks, such as diabetes and cancer. Yet, research is conflicting for use of the waist-to-hip ratio where some studies have shown that the ratio is not a good predictor of health problems.

If you are looking for more specifics and percentages of your body fatness, speak to your doctor about other possible measurements that require equipment such as: the dual energy x-ray absorptiometry (DEXA) which is frequently used to test bone density; bioelectrical impedance (BIA) or body fat meters. which use an electric current to measure resistance and determine body fat percentage; or skinfold thickness measurement using calipers that pinch the skin to determine the fat layer underneath the skin. In summary, to determine your weight status in a quick and inexpensive way, use a combination of your BMI, waist circumference, and waist-to-hip ratio. While each of these methods have some pros and cons, they still provide some insight into your weight and health status.

Rhea Li is a Registered Dietitian who received her Bachelor's degree in Nutrition and Master's degree in Public Health from the University of Texas. She has a special interest in working with children and has received her certification in pediatric weight management. Currently, she is working on a research study to determine the importance of nutrition in pediatric cancer patients. In the past, she has worked with pregnant women and their children. In her spare time, she enjoys being with family, exercising, traveling and of course, eating. To contact Rhea, please visit dazzlingdietitian.blogspot.com or her Twitter account, Rhea_Li.

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