The body mass index chart makes determining your BMI easier than using the BMI formula. The BMI is a tool used by doctors to assess the possibility of a patient developing obesity-related conditions, such as sleep apnea and diabetes, according to the National Library of Medicine.
Formula
To determine your BMI, multiply your height in inches by your height in inches, which is your height squared. Then, divide your weight in pounds by the result of your height squared. Finally, you multiply that result by 703. The resulting number is your body mass index. For example, if you are 6 feet tall (72 inches) and weight 175 lbs., you would figure your BMI as follows:
72 inches x 72 inches = 5184
175 lbs / 5184 = 0.0337
0.0337 x 703 = 23.69
BMI = 23.69
Types
There are two types of BMI charts. One is for children and the other is for adults. The child's BMI chart is used for patients from 2 years old to 20 years old. It is based on age, weight and height. The adult BMI chart is based only on weight and height.
Ratings
A normal BMI for an adult is anything from 18.5 to 24.9. Anything under that is considered underweight. A BMI from 25.0 to 29.9 is considered overweight. From 30.0 to 39.9 is considered obese, and anything over that is considered morbidly obese, according to the National Library of Medicine.
For children, the BMI chart is based on percentiles, according to the Nemours Foundation. A child who is at or under the fifth percentile is said to be underweight. Normal includes the fifth to 84th percentiles. Overweight includes the 85th to 94th percentiles. And, anything higher than the 94th percentile is considered obese.
Alternatives
Body fat measurements, waist circumference measurements, dual energy X-ray absorptiometry, bioelectrical impedance, isotope dilution, waist-to-hip ratios and underwater weighing are alternative tests that can be used instead of the BMI chart to determine the risk of obesity-related conditions. These methods are often more costly and less regulated than BMI charts, according to the Centers for Disease Control and Prevention. In some cases, these alternatives are used in conjunction with the BMI chart to get a more accurate risk assessment.
Considerations
Because the BMI chart is a generalized method of determining the risk of obesity-related conditions, the BMI chart is not accurate for everyone. According to the National Heart Lung and Blood Institute, the BMI chart sometimes underestimates the amount of body fat in an elderly person or overestimates the amount in an athlete.
Member Comments