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. The higher the BMI, the greater the risk of developing additional health problems. 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 .

The NHLBI obesity guidelines propose that doctors use body mass index (BMI) to assess patients because the index is simple, correlates to fatness and applies to both men and women. To determine BMI, weight in kilograms is divided by height in meters, squared.

In June 1998, the federal government announced guide-lines 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 consider-ed overweight. Those with BMI's of 18.5 or less are considered under-weight. A BMI of 30 or over is considered obese.

Use our BMI Calculator to calculate your body mass index.

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 measurement, 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