A disorder that involves having too much body fat, which increases the risk of health problems.

Obesity is a disorder that involves having too much body fat, usually a body mass index — also known as BMI — of 30 or greater. It increases the risk of serious health problems. Obesity often results from taking in more calories than are burned by exercise and typical daily activities.

Body mass index, also known as BMI, is often used to diagnose obesity. Many health care professionals also measure around a person's waist to help guide treatment decisions. This measurement is called a waist circumference.

Treatments include lifestyle changes, medicines and weight-loss surgery.