Being obese increases your risk for several diseases. If you don't know whether your weight puts you at risk, the first step is to find out your body mass index (BMI). Keep in mind that BMI should not be used to determine your "ideal" weight. Instead, use it as the first step to check whether you are at a healthy weight.

According to the BMI, which is based on your height and weight, you are considered overweight if your BMI is between 25 and 29.9. If your BMI is 30 or above, you are considered obese.⁴

Based on federal obesity guidelines, an elevated BMI alone is not an adequate measure of your risk for disease. Other risk factors, such as a large waist measurement, inactivity, and smoking, are part of the equation.⁴

If your BMI is higher than recommended, your doctor may then measure your waist. In men, a waist measurement greater than 40 in. is considered a health risk. Women who have a waist size larger than 35 in. are considered at risk for disease.

Diseases associated with obesity and a large waist measurement include:

• High cholesterol and cardiovascular disease (including coronary artery disease and stroke).
• High blood pressure (hypertension). People who are obese have a risk for high blood pressure that is 2 to 3 times greater than that of people who maintain a healthy weight.⁵
• Sleep apnea and respiratory problems.
• Type 2 diabetes.
• Gallbladder disease (gallstones). People who are overweight have a risk for gallbladder disease that is 2 to 3 times greater than that of people who maintain a healthy weight.⁵
• Metabolic syndrome. Research has shown that having this syndrome increases your risk for coronary artery disease (CAD), even beyond that caused by high cholesterol alone.⁶
• Osteoporosis.
• Osteoarthritis.
• Some forms of cancer, such as colon, breast, and prostate.

For more information on health risks, see the topic Obesity.