WebMD
Font Size
A
A
A

Body mass index, waist size, and risk for disease

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 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 - -
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

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. Being underweight may also result in depression and other mental health conditions.

Author Caroline Rea, RN, BS, MS
Editor Susan Van Houten, RN, BSN, MBA
Associate Editor Pat Truman
Primary Medical Reviewer Caroline S. Rhoads, MD
- Internal Medicine
Specialist Medical Reviewer Matthew I. Kim, MD
- Endocrinology & Metabolism
Last Updated April 20, 2007

WebMD Medical Reference from Healthwise

Last Updated: April 20, 2007
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.