The Limitations Of BMI

Reasonable Predictors
Body Mass Index or BMI is frequently used by healthcare providers as a weight assessment tool and is derived by dividing body weight in kilograms by height in meters squared (BMI=kg/m²). Or, if you prefer, divide weight in pounds by height in inches squared, then multiply the result by 703.

Example: Weight = 150 lbs, Height = 5'5" (65")

Calculation: [150 ÷ (65)²] x 703 = 24.96

While it is a reasonable predictor of individual risk for developing chronic diseases and obesity related health problems, it has limitations. For example, BMI does not take into account the difference between excess fat and muscle. Consequently, fit and healthy people with a high proportion of muscle tissue can be erroneously classified as overweight. BMI measures total body weight, not the actual amount of fat a person is carrying. Some people are naturally stocky and have a body mass index that is in the overweight category, when in fact their weight is due to muscle mass and a heavier bone structure rather than excess fat.

Relying on BMI, scales, or even body fat measurements alone can paint an inaccurate picture of realistic weight goals. It is more important to attain a healthy weight based upon several factors, including: Family history, medical history, body-fat distribution and body composition.

Family history takes into account genetic factors, including physical characteristics that are good predictors when trying to establish weight loss and management goals. Medical history is valuable in assessing health risk factors and establishing weight loss goals that may be appropriate for type II diabetes, heart disease, high blood pressure, etc. Body-fat distribution (aka waist-to-hip ratio – WHR) is valuable in determining risk because body fat located in the upper body (especially around the stomach area) is a greater indicator of heart disease, diabetes and prostate cancer than weight around the hips.

Using a compilation of assessments may actually be the best way to determine healthy weight that is compatible with body type, genetics, fitness and wellness levels. The ability to perform everyday activities, including job and leisure-time hobbies or pursuits is also a key part in determining healthy lifestyle. If an individual’s excessive weight hinders their ability to engage in functional activities, it is a good idea to try to attain a weight level that allows for a healthy, active life

Ref: -The Better Life Experts | April 16, 2009
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