Body Mass Index

As a part of healthy aging, it pays to understand your body mass index (BMI), a measure of body fat based on height and weight that applies to both adult men and women.

The National Heart, Lung, and Blood Institute (NHLBI) has a Web site that lets you easily calculate your BMI just by entering your current height and weight. Visit www.nhlbisupport.com/bmi/bmicalc.htm to learn your BMI.

BMI Categories:

  • Underweight = <18.5
  • Normal weight = 18.5-24.9
  • Overweight = 25-29.9
  • Obesity = BMI of 30 or greater

According to the NHLBI guidelines, assessment of overweight involves using three key measures:

  • body mass index (BMI)
  • waist circumference, and
  • risk factors for diseases and conditions associated with obesity.


Waist Circumference

Determine your waist circumference by placing a measuring tape snugly around your waist. It is a good indicator of your abdominal fat, which is another predictor of your risk for developing risk factors for heart disease and other diseases. This risk increases with a waist measurement of over 40 inches in men and over 35 inches in women.

Besides being overweight or obese, there are other risk factors to consider:

  • high blood pressure (hypertension)
  • high LDL-cholesterol (“bad” cholesterol)
  • low HDL-cholesterol (“good” cholesterol)
  • high triglycerides
  • high blood glucose (sugar)
  • family history of premature heart disease
  • physical inactivity
  • cigarette smoking


For people who are considered obese (BMI greater than or equal to 30) or those who are overweight (BMI of 25 to 29.9) and have two or more risk factors, the guidelines recommend weight loss. Even a small weight loss (just 10 percent of your current weight) will help to lower your risk of developing diseases associated with obesity. Patients who are overweight, do not have a high waist measurement, and have fewer than two risk factors may need to prevent further weight gain rather than lose weight.

Disclaimer: Consult a physician before beginning any diet, nutrition or exercise program. The information on this website is not intended to replace medical advice or a relationship with a qualified doctor or health care professional. It is not intended as medical advice of any kind. Individual articles and information are based upon the opinions of the respective author, who retains copyright as marked. The views represented by contributing authors do not necessarily reflect those of Keith Ahrens or his associates. Some content has been reprinted with permission, U.S. Department of Health and Human Services, National Institutes of Health, National Heart Lung and Blood Institute. No part of this website may be reproduced without the expressed written permission of Keith A. Ahrens.