The obesity epidemic among adults in the United States continues to rise. Latest data from the CDCÃ¢â‚¬â„¢s Behavioral Risk Factor Surveillance System show that an estimated 25.6 percent of U.S. adults reported being obese in 2007, an increase of 1.7 percent from 23.9 percent in 2005. Alabama, Mississippi and Tennessee lead the way with all three states reporting an obesity prevalence of above 30 percent. Colorado had the lowest obesity prevalence at 18.7 percent. Obesity is defined as a body mass index (BMI) of 30 or above. BMI is calculated using height and weight. By region, the report also finds that obesity is more prominent in the South, where 27 percent of respondents were classified as obese, compared with 25.3 percent in the Midwest, 23.3 percent in the Northeast, and 22.1 percent in the West. Check out I.I.I. information on obesity liability.