Obesity is a condition in which a person has an abnormally high and unhealthy body fat ratio.
To measure obesity, researchers often use a scale known as the body mass index (BMI). BMI is calculated by dividing a person’s weight (in kilograms) by your height (in meters) squared. BMI provides a more accurate picture of obesity or overweight separately measured weight.
Results from the 2007-2008 National Survey of Health and Nutrition Examination Survey (NHANES) show that 68 percent of US adults age 20 and older are overweight or obese. In 1988-1994, however, only 56 percent of adults aged 20 years or older are overweight or obese.
In addition, the percentage of children who are overweight or obese has also increased. Among children and teens ages 2-19, 17 percent are estimated to be obese, based on the survey 2007-2008. In 1988-1994, the figure was only 10 percent.