According to the National Heart, Lung & Blood Institute (NHLBI) guidelines, assessment of obesity involves three key measures:

1. Body Mass Index (BMI)
2. Waist circumference
3. Risk factors for diseases and conditions
    associated with obesity

BMI is a reliable indicator of total body fat, which is related to the risk of disease and death.  The score is valid for both men and women.  However, it may overestimate body fat in athletes and others with a muscular build and may underestimate body fat in older persons and others who have lost muscle mass.  Use BMI Tables to estimate your total body fat. Click the Back button on your browser to return to this spot.

Interpret your BMI score using the following table which applies to adults ages 18 and up:

Below 18.5 Underweight
18.5 - 24.9 Normal
25.0 - 29.9 Overweight
30.0 and Above Obese

Your Healthy Weight & Healthy Weight Range

Your healthy weight range is between a BMI of 18.5 and 24.9.  Click here to see if you are in the healthy weight range.  Use the Back button on your browser to return to this spot.

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

The table, Risks of Obesity-Associated Diseases by BMI and Waist Circumference, provides you with an idea of whether your BMI combined with your waist circumference increases your risk for developing obesity-associated diseases or conditions.  Use the Back button on your browser to return to this location.

Besides being overweight or obese, there are additional 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

Overall Risk Assessment

Based on the NHLBI guidelines you should lose weight if:
you have a BMI greater than or equal to 30 (Obese)
you have a BMI of 25 to 29.9 (Overweight) and have 2
        or more risk factors

Even a small weight loss (just 10 percent of your current weight) will help to lower your risk of developing diseases associated with obesity.

Please note that BMI is used differently with children than it is with adults.  According to the Centers for Disease Control (CDC), in children and teens body mass index is used to assess underweight, overweight and risk for overweight.  Children's body fatness changes over the years as they grow.  Also, girls and boys differ in their body fatness as they mature.  This is why BMI for children, also referred to as BMI-for-age, is gender and age specific.  Click to visit CDC website to review Age Specific Charts.

You should always talk to your doctor about your risk factors and also before embarking on any weight loss or exercise program.

Source: National Heart, Lung & Blood Institute (NHLBI) & CDC Websites