Mind & Body
Body Mass Index and Health
Your body mass index or BMI is a tool that is used by physicians, dieticians and nutritionists to determine whether an individual's weight and body fat is in a healthy range. BMI is calculated by dividing the individual's weight by total body surface area. The BMI score and interpretation scale are valid for both men and women, but BMI does have several limitations. BMI alone cannot be used to determine whether an individual is healthy, underweight, overweight or obese. Waist circumference must also be measured and accounted for. Otherwise, muscular individules with high weights but low body fat could be classified as overweight. Similarly, in older people who have lost muscle, body fat may be underestimated. Waist circumference is also important because carrying fat around the waistline is associated with more health risks than fat around the hips.

[ BMI Calculator ]
[ BMI Chart ]
Your Weight (lbs)
Your Height (inches)
Your BMI

click here to calculate your BMI using a table (pdf)

Results: Underweight Healthy Overweight Obese
<19 19-25 26-30 >30

Limitations of BMI
Health risks increase if your waist is over 40 inches for men and over 35 inches for women. Muscular individuals with waist measurements lower than these guidelines are likely to have their body fat overestimated by the BMI index. Older individuals with less muscle may have their body fat underestimated by these guidelines. In order to assess your body fat and health risks, consult your physician.

Chart provided by NIDDK, NIH for distribution

[ Obesity Prevalence ]
[ Increased Risk ]

Above a BMI of 20, the risk for a number of health conditions increases as BMI increases. In medical studies, people who are overweight or obese have been found to have a higher risk for high blood pressure, high cholesterol, type 2 diabetes, heart disease, strokes, gallbladder disease, arthritis, sleep apnea and respiratory problems, and some types of cancer (endometrial, breast, prostate, and colon). Obesity is also associated with complications of pregnancy, menstrual irregularities, abnormal facial hair, stress incontinence, and psychological disorders.

Map provided by Center for Disease Control

[ References ]
[ Certification ]

Clinical Guidlines on the Identification, Evaluation, an Treatment of Overweight and Obesity in Adults: The Evidence Report. NIH Publication No. 98-4083. September 1998. National Heart, Lung, and Blood Institute in cooperation with the National Institute of Diabetes and Digestive and Kidney Diseases.

The information in this document was written by:
Carl Miller, University of Michigan Medical School

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