Body Mass Index (BMI) is one of the most accurate ways to determine when extra pounds translate into health risks. BMI is a measure which takes into account a person’s weight and height to gauge total body fat in adults. Someone with a BMI of 26 to 27 is about 20 percent overweight, which is generally believed to carry moderate health risks. A BMI of 30 and higher is considered obese. The higher the BMI, the greater the risk of developing additional health problems.

Heart disease, diabetes and high blood pressure are all linked to being overweight. A BMI of 30 and over increases the risk of death from any cause by 50 to 150 percent, according to some estimates. According to health experts, people who are overweight but have no other health risk factors (such as high cholesterol or high blood pressure) should eat healthier and exercise to keep from gaining additional weight. For people who are overweight and also have health risks, they recommend trying to actively lose weight. Be sure to consult your doctor or other health professional before beginning any exercise or weight-loss program.

In June 1998, the federal government announced guidelines which create a new definition of a healthy weight -- a BMI of 24 or less. So now a BMI of 25 to 29.9 is considered overweight. Individuals who fall into the BMI range of 25 to 34.9, and have a waist size of over 40 inches for men and 35 inches for women, are considered to be at especially high risk for health problems.

Use the BMI CALCULATOR below to figure your BMI and then refer to the chart to see ranges for a healthy BMI.

To use the table below, find the appropriate height in the left-hand column. Move across to a given weight. The number at the top of the column is the BMI for that height and weight. Pounds have been rounded off. SOURCE: National Heart, Lung, and Blood Institute.

Both Body Mass Index (BMI) and Waist Circumference (WC) can be useful measures of determining obesity and increased risk for various diseases. According to the National Institutes of Health, a high WC is associated with an increased risk for type 2 diabetes, dyslipidemia, hypertension and cardiovascular disease when BMI is between 25 and 34.9. (A BMI greater than 25 is considered overweight and a BMI greater than 30 is considered obese.) WC can be useful for those people categorized as normal or overweight in terms of BMI. (For example, an athlete with increased muscle mass may have a BMI greater than 25 - making him or her overweight on the BMI scale - but a WC measurement would most likely indicate that he or she is, in fact, not overweight). Changes in WC over time can indicated an increase or decrease in abdominal fat. Increased abdominal fat is associated with an increased risk of heart disease.

To determine your WC, locate the upper hip bone and place a measuring tape around the abdomen (ensuring that the tape measure is horizontal). The tape measure should be snug but should not cause compressions on the skin. The following chart should be helpful in determining the possible risks associated with your BMI and WC.

*     Disease risk for type 2 diabetes, hypertension, and CVD.
+     Increased waist circumference can also be a marker for increased risk even in persons of normal weight.
SOURCE: National Heart, Lung and Blood Institute