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 diseases
Classification BMI Waist size and relative risk

Men: less than or equal to 102 cm (40 in.)

Women: less than or equal to 88 cm (35 in.)

Men: more than 102 cm (40 in.)

Women: more than 88 cm (35 in.)

Normal 18.5–24.9
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

Waist size cutoff may be lower for some people.

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


ByHealthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Brian D. O'Brien, MD - Internal Medicine
Specialist Medical Reviewer Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator

Current as ofFebruary 20, 2015