Waist circumference is a quick measurement that may be used to assess your disease risk, similar to the information provided from BMI results.
Other simple measurements (mid-upper arm, hip, and mid-thigh circumferences) may also be taken to show you body changes that your body may be undergoing that you are not necessarily noticing on your own.
Body composition plays a large role in showing you the progress that you have made that you may not see on the scale right away. You may lose several inches before you begin shedding pounds and progress is always encouraging!