Body Mass Index (BMI)

Body mass index (BMI) is a number based on a person’s weight and height that provides a way to estimate the effect of weight on health. The higher the BMI, the greater the risk of some diseases, including high blood pressure, coronary artery disease, stroke, osteoarthritis, some cancers, and type 2 diabetes. To…

Body Mass Index (BMI)

Body mass index (BMI) is a number based on a person's weight and height that provides a way to estimate the effect of weight on health. The higher the BMI, the greater the risk of some diseases, including high blood pressure, coronary artery disease, stroke, osteoarthritis, some cancers, and type 2 diabetes.

To calculate exact BMI, one of the following equations is used:

  • The person's weight in pounds and height in inches: BMI = (pounds x 703) divided by (inches squared)
  • The person's weight in kilograms and height in meters: BMI = kilograms divided by (meters squared)

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Body Mass Index (BMI)

Your body mass index (BMI) and waist size affect your risk of type 2 diabetes, high blood pressure, high cholesterol, and coronary artery disease. The following table shows the risk. Body mass index (BMI) and the risk for diseases 1 Classification BMI Waist size and relative risk Men: less than 40 in. (102 cm) Women…

Body Mass Index (BMI)

Topic Overview

Your body mass index (BMI) and waist size affect your risk of type 2 diabetes, high blood pressure, high cholesterol, and coronary artery disease. The following table shows the risk.

Body mass index (BMI) and the risk for diseasesfootnote 1

Classification

BMI

Waist size and relative risk

Men: less than 40 in. (102 cm)

Women: less than 35 in. (88 cm)

Men: 40 in. (102 cm) or more

Women: 35 in. (88 cm) or more

Normal

18.5–24.9

Increased risk

Overweight

25–29.9

Increased risk

High risk

Obesity I

30–34.9

High risk

Very high risk

Obesity II

35–39.9

Very high risk

Very high risk

Obesity III (extreme)

40 or above

Extremely high risk

Extremely high risk

For Asian people, each risk category may include lower BMIs than those listed in the table.

A BMI under 18.5 is considered unhealthy. There is risk that you are not getting sufficient nutrition (malnutrition). Complications of malnutrition include anemia, nutrient deficiency, heart irregularities, loss of menstrual periods in women (amenorrhea), cavities, and osteoporosis.

Related Information

References

Citations

  1. National Heart, Lung, and Blood Institute, National Institutes of Health (2000). The Practical Guide: Identification, Evaluation, and Treatment of Overweight and Obesity in Adults (NIH Publication No. 00-4084). Available online: http://www.nhlbi.nih.gov/guidelines/obesity/prctgd_c.pdf.

Credits

Current as ofMarch 28, 2019

Author: Healthwise Staff
Medical Review: E. Gregory Thompson, MD - Internal Medicine
Kathleen Romito, MD - Family Medicine
Martin J. Gabica, MD - Family Medicine
Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator

This information does not replace the advice of a doctor. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.