Thanks to industrialization, food is readily available in abundant amounts. This has its drawbacks, however, as obesity and overweight become health epidemics in many countries. Population assessment tools are needed to keep track of this growing problem. Body mass index, or BMI, is one such tool. Because it is easily standardized and implemented, using BMI to estimate weight problems allows large population samples to be assessed. It is also simple for individuals to use.
The Formula
Body mass index is calculated from a formula that uses a person's height and weight. If you measure weight in kilograms and height in meters, use the formula weight/height^2 to figure out your BMI. If you use pounds and inches, use the formula (weight/height^2) x 703. If your resulting number is below 18.5, you are considered underweight. If it is between 18.5 and 24.9, you are of normal weight. If your BMI is between 25.0 and 29.9, you are overweight, and if it is 30.0 or more, you are obese.
History
The Body mass index formula, also known as the "Quetelet Index," was developed by Lambert Adolphe Jacques Quetelet in the mid 1800s. Working for life insurance companies, Quetelet came up with the formula while researching factors related to birth and death. In the 1980s, this formula became a popular measurement of overweight and obesity in the United States. Prior to BMI, the standard used to assess healthy weights was the Metropolitan Life Insurance Company's height and weight chart.
Significance
Body Mass Index is a generally reliable measurement that suggests whether a person has an unhealthy amount of body fat or not. It can be used to measure a person's risk for developing weight-related health problems. Since it has some limitations, BMI should be used in part with other assessment tools for better accuracy. Body mass index is also used to assess the weight problems and weight-related health risks of general populations.
Benefits
If your BMI and a related assessment, such as waist circumference measurement, skinfold thickness measurement, diet and physical activity evaluations, or family history, indicate that you have a weight problem, you can begin to take the steps necessary to get your weight under control and become healthy. Government health organizations use the BMI information of large populations to promote striving for healthy weights though diet and exercise, and raise awareness of the problems associated with overweight and obesity.
Considerations
Since BMI is not a direct measurement of body fat, it is not 100 percent accurate, and it is not a diagnostic tool. Excess weight is not always a health risk, as in the case of athletes whose extra weight is made up of muscle. The correlation between BMI and body fat levels varies among the different sexes, races and age groups. For example, women have more body fat than men of the same BMI, and older people tend to have more body fat than younger people of the same BMI.
Member Comments