What is obesity?
How do you know if you are obese?
You can use a measurement called a body mass index, or BMI, along with your waist size, to decide whether your weight is dangerous to your health. The BMI is a combination of your height and weight. If you have a BMI of 30 or higher, unhealthy eating patterns, and too little physical activity, your extra weight is putting your health in danger.
Use the Interactive Tool: Is Your BMI Increasing Your Health Risks? to find out your body mass index.
Use the Interactive Tool: What Is Your Child's BMI? to check BMI in children ages 2 to 19.
People who carry too much fat around the middle, rather than around the hips, are more likely to have health problems. In women, a waist size of 35 in. (88 cm) or more raises the chance for disease. In men, a waist size of 40 in. (101 cm) or more raises the chance for disease.1
If you are Asian, your health may be at risk if you have a BMI of 27.5 or higher and you have unhealthy eating patterns and too little physical activity. Also, health problems are seen with a smaller waist size. In Asian women, a waist size of 32 in. (80 cm) or more raises the chance for disease. In Asian men, a waist size of 36 in. (90 cm) or more raises the chance for disease.2
Check this table to find your risk for disease using your body mass index and waist size.
What causes obesity?
When you take in more calories than you burn off, you gain weight. How you eat, how active you are, and other things affect how your body uses calories and whether you gain weight.