According to the National Heart Lung and Blood Institute (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
BMI is a measure of body fat based on height and weight that applies to both adult men and women; waist circumference measures abdominal fat. Combining these with information about your additional risk factors yields your risk for developing obesity-associated diseases.
Body Mass Index (BMI)
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 but it does have some limits. The limits are:
- It may overestimate body fat in athletes and others who have a muscular build
- It may underestimate body fat in older persons and others who have lost muscle mass
Use the BMI calculator to estimate your total body fat. Enter your height and weight and press the "Compute BMI" button. Your BMI and rating will be displayed in the results table.
The BMI score means the following:
- Underweight = <18.5
- Normal weight = 18.5-24.9
- Overweight = 25-29.9
- Obesity = BMI of 30 or greater
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
Other Risk Factors
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
Assessment
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% 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 less than two risk factors may need to prevent further weight gain rather than lose weight.
Talk to your physician to see if you are at an increased risk and if you should lose weight. Your doctor will evaluate your BMI, waist measurement, and others risk factors for heart disease. People who are overweight or obese have a greater chance of developing high blood pressure, high blood cholesterol or other lipid disorders, type 2 diabetes, heart disease, stroke, and certain cancers, and even a small weight loss (just 10% of your current weight) will help to lower your risk of developing those diseases.