Obesity is associated with reduced quality of life, development of serious chronic conditions such as heart disease and diabetes, increased medical care costs, and premature death. A Healthy People 2010 objective is to reduce to 15% the proportion of adults who are obese. In 2005, no state met this target, and (based on self-reported height and weight) 23.9% of adults in the United States were obese. To update 2005 estimates of the prevalence of obesity in adults, CDC analyzed data from the 2007 Behavioral Risk Factor Surveillance System (BRFSS) survey. The results of that analysis indicated that 25.6% of respondents overall in 2007 were obese; the prevalence of obesity among adults remained above 15% in all states and was above 30% in Alabama, Mississippi, and Tennessee. Enhanced collaborative efforts among national, state, and community groups are needed to establish, evaluate, and sustain effective programs and policies to reduce the prevalence of obesity in the United States.