This is the fattest state in America by John Kell @FortuneMagazine September 21, 2015, 2:53 PM EDT E-mail Tweet Facebook Linkedin Share icons Arkansas has the highest adult obesity rate among all 50 states, according to the latest report on obesity from the Trust for America’s Health and the Robert Wood Johnson Foundation. U.S. adult obesity rates remained mostly steady, but high, over the past year, the report found, rising in Kansas, Minnesota, New Mexico, Ohio, and Utah, but remaining stable in the rest. Nationally, more than 30% of adults are obese, a stark increase from 1980 when no state had a rate above 15%. In 1990, no state had an obesity rate above 20%. Now, obesity rates are at or above 30% in 22 states, according to the report. Rounding out the top five states with the highest obesity rates were West Virginia, Mississippi, Louisiana, and Alabama. The states with the lowest obesity rates were Colorado (the best performer), followed by Hawaii, Massachusetts, California, and Vermont. The District of Columbia would have ranked between Colorado and Hawaii if it were a state. The report found that 23 of 25 states with the highest obesity rates were in the South and Midwest, while seven out of 10 with the highest rates were in the South. Obesity rates were higher for African Americans and Latinos than for Whites, the report found. Obesity is a costly epidemic, adding $147 billion to annual medical costs in the U.S., according to the Centers for Disease Control and Prevention. The latest obesity report says 78 million Americans are at risk for a number of obesity-related health woes, including heart disease and diabetes.