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Body Mass Index (BMI)

Topic Overview

Yourbody mass index (BMI)and waist sizeaffect your risk oftype 2 diabetes,high blood pressure,high cholesterol, andcoronary artery disease. The following table shows the risk.

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



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




Increased risk



Increased risk

High risk

Obesity I


High risk

Very high risk

Obesity II


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



  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:


ByHealthwise Staff
Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine
Kathleen Romito, MD - Family Medicine
Martin J. Gabica, MD - Family Medicine
Specialist Medical ReviewerRhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator

Current as ofOctober 9, 2017

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