Science offers two methods for assessing body fat. While they're not perfectly accurate, they both tell you whether, and how urgently, you need to take steps to control your weight and reduce your cancer risk.

1. Body Mass Index (BMI)*

Body Mass Index is one common method used to measure overweight and obesity. BMI is a measure of body fat based on a person's weight and height. The BMI chart shows four ranges: underweight, healthy, overweight and obese. Staying within the healthy range throughout life is important for lowering your cancer risk.

2. Waist Circumference

Waist circumference is another method of assessing your body weight. All you need to do is find a tape measure and follow these easy steps.

1. Place a tape measure around your waist above the tip of your hipbone.
2. Measure your waist after exhaling.
3. Determine your health risk. For women, a waist measurement of 31.5 inches or more indicates high risk. For men, a waist measurement of 37 inches or more indicates high risk.

*BMI may not be an accurate measure for everyone — including people who have more muscle mass (like athletes), seniors with less muscle mass or people under 5 feet tall. If you are at high risk, learn how you can lose weight.
If you are not at risk, learn how to prevent weight gain.