Body Mass Index (BMI)Skip to the navigation
|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
|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.
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator
Current as ofMarch 12, 2014
Current as of: March 12, 2014