What Is It?
Obesity is an excess of body fat.
It is difficult to directly measure body fat. Body mass index (BMI) is a popular method of defining a healthy weight. BMI should be used as a guide, along with waist size, to help estimate the amount of body fat.
BMI estimates a healthy weight based on your height. Because it considers height as well as weight, it is a more accurate guide than body weight alone.
To calculate your BMI:
Multiply your weight in pounds by 703
Divide that answer by your height in inches
Divide that answer by your height in inches again
Then use the chart below to see what category your BMI falls into.