http://www.cdc.gov/nccdphp/dnpa/bmi/bmi-adult.htm
Body Mass Index or BMI is a tool for indicating weight status in adults.1 It is a measure of weight for height. For adults over 20 years old, BMI falls into one of these categories:
BMI Weight Status
Below 18.5Â* UnderweightÂ*
18.5 – 24.9Â* NormalÂ*
25.0 – 29.9Â* OverweightÂ*
30.0 and AboveÂ* ObeseÂ*
Note: BMI for Children and Teens is based on gender and age specific charts.
BMI correlates with body fat. The relation between fatness and BMI differs with age and gender. For example, women are more likely to have a higher percent of body fat than men for the same BMI. On average, older people may have more body fat than younger adults with the same BMI.2
For more information about overweight among adults, see Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. Bethesda, MD: NHLBI, 1998.
How does BMI relate to health?
The BMI ranges are based on the effect body weight has on disease and death.3 As BMI increases, the risk for some disease increases. Some common conditions related to overweight and obesity include4
Premature death
Cardiovascular disease
High blood pressure
Osteoarthritis
Some cancers
Diabetes
BMI is only one of many factors used to predict risk for disease. BMI cannot be used to tell a person if he/she has a disease such as diabetes or cancer. It is important to remember that weight is only one factor that is related to disease.
How to calculate BMI
You can cheat and go here for a pre-calculated chart that shows you your BMI based on your height and weightÂ*
http://www.cdc.gov/nccdphp/dnpa/bmi/...bmi-adults.pdf
or you can calculate it yourself down below:
English Formula
Body Mass Index can be calculated using pounds and inches with this equation
BMI = (Weight in Pounds(Height in inches) x (Height in inches) ) x 703
For example, a person who weighs 220 pounds and is 6 feet 3 inches tall has a BMI of 27.5.
(220 lbs.(75 inches) x (75 inches) ) x 703 = 27.5
Metric Formula
Body Mass Index can also be calculated using kilograms and meters (or centimeters).
BMI =Weight in Kilograms(Height in Meters) x (Height in Meters)Â* Â*
Â* orÂ* Â*
BMI = (Weight in Kilograms(Height in centimeters) x (Height in centimeters) ) x 10,000
For example, a person who weighs 99.79 Kilograms and is 1.905 Meters (190.50 centimeters) tall has a BMI of 27.5.
99.79 Kg(1.905 m) x (1.905 m) = 27.5
What Does This All Mean?
BMI is not the only indicator of health risk.
BMI is just one of many factors related to developing a chronic disease (such as heart disease, cancer, or diabetes). Other factors that may be important to look at when assessing your risk for chronic disease include:
Diet
Physical Activity
Waist Circumference
Blood Pressure
Blood Sugar Level
Cholesterol Level
Family History of disease
BMI Weight Status
Below 18.5 Underweight
18.5 – 24.9 Normal
25.0 – 29.9 Overweight
30.0 and Above Obese
All persons who are obese or overweight should try not to gain additional weight. In addition, those who are obese or who are overweight with other risk factors should consider losing weight. A complete health assessment by a physician is the best way to decide the right steps for you.
Whatever your BMI, talk to your doctor to see if you are at an increased risk for disease and if you should lose weight. Even a small weight loss (just 10% of your current weight) may help to lower the risk of disease.
Physical activity and good nutrition are key factors in leading a healthy lifestyle and reducing risk for disease. Visit our Resource Section for links to information on BMI, obesity, physical activity and nutrition.
Common Myths
Myth: BMI Measures Body Fat
Two people can have the same BMI, but a different percent body fat. A bodybuilder with a large muscle mass and a low percent body fat may have the same BMI as a person who has more body fat because BMI is calculated using weight and height only.
These men have the same height, weight, and BMI, but may have different percent body fat.
6'3"Â* HeightÂ* 6'3"Â*
220 lbsÂ* WeightÂ* 220 lbsÂ*
27.5Â* BMIÂ* 27.5Â*
Â*
This is a good reminder that BMI is only one piece of a person's health profile. It is important to talk with your doctor about other measures and risk factors. (e.g., waist circumference, smoking, physical activity level, and diet.)
Myth: BMI is a diagnostic tool
BMI alone is not diagnostic. It is one of many risk factors for disease and death. As a person's BMI increases the risk for many diseases increases as well.
References
1 Garrow JS and Webster J. Quetelet's index (W/H2) as a measure of fatness. International Journal of Obesity 1985;9:147–153.
2 Gallagher D, et al. How useful is BMI for comparison of body fatness across age, sex and ethnic groups? American Journal of Epidemiology 1996;143:228–239.
3 World Health Organization. Physical status: The use and interpretation of anthropometry. Geneva, Switzerland: World Health Organization 1995. WHO Technical Report Series.
4 Calle EE, et al. BMI and mortality in prospective cohort of U.S. adults. New England Journal of Medicine 1999;341:1097–1105.
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Date last reviewed: 12/16/2004
Content source: Division of Nutrition and Physical Activity, National Center for Chronic Disease Prevention and Health Promotion