A new analysis shows that 12 U.S. states have an adult obesity rate above 30 percent.

Obesity prevalence ranged from 20.7% in Colorado to 34.9% in Mississippi in 2011. No state had a prevalence of obesity less than 20%. 39 states had a prevalence of 25% or more; 12 of these states had a prevalence of 30% or more: Alabama, Arkansas, Indiana, Kentucky, Louisiana, Michigan, Mississippi, Missouri, Oklahoma, South Carolina, Texas, and West Virginia.

Minnesota's prevalence is 25.7%.

The South had the highest prevalence of obesity (29.5%), followed by the Midwest (29.0%), the Northeast (25.3%) and the West (24.3%).

In 2006, obesity-related medical costs totaled $147 billion a year, or nearly 10 percent of total medical spending, according to a 2011 study in Health Affairs. The bulk of the spending is from treating obesity-related diseases, such as diabetes.

But in the good news department, the CDC recently reported that 62 percent of adults say they walked at least once for 10 minutes or more in the previous week in 2010, compared to 56 percent in 2005.

The new analysis was released today by the Trust for America's Health and the Robert Wood Johnson Foundation (RWJF), using state obesity rates from the U.S. Centers for Disease Control and Prevention.

Read more from the Centers for Disease Control and Prevention.