Since 2005, there has been some evidence that the rate of increase has been slowing. In 2005, every state but one experienced an increase in obesity rates; in 2008, rates increased in 37 states; in 2010, rates increased in 28 states; and in 2011, rates increased in 16 states.

"While stable rates of adult obesity may signal prevention efforts are starting to yield some results, the rates remain extremely high," said Jeffrey Levi, Ph.D., executive director of TFAH. "Even if the nation holds steady at the current rates, Baby Boomers -- who are aging into obesity-related illnesses -- and the rapidly rising numbers of extremely obese Americans are already translating into a cost crisis for the healthcare system and Medicare."

Levi added, "In order to decrease obesity and related costs, we must ensure that policies at every level support healthy choices, and we must focus investments on prevention."

Key findings from the 2013 "F as in Fat" report include:

• Rates vary by region. Of the states with the 20 highest adult obesity rates, only Pennsylvania is not in the South or Midwest. For the first time in eight years, Mississippi no longer has the highest rate -- Louisiana at 34.7% is the highest, followed closely by Mississippi at 34.6%. Colorado had the lowest rate at 20.5%.
• Rates vary by age. Obesity rates for Baby Boomers (45-to 64-year-olds) have reached 40% in two states (Alabama and Louisiana) and are 30% or higher in 41 states. By comparison, obesity rates for seniors (65+ years old) exceed 30% in only one state (Louisiana). Obesity rates for young adults (18-to 25-year-olds) are below 28% in every state. 
• Rates by gender are now consistent. Ten years ago, there was nearly a six percentage point difference between rates for men and women (men: 27.5%, women: 33.4%), and now rates are nearly the same (men: 35.8%, women 35.5%). Men's obesity rates have been climbing faster than women's for this last decade.
• Rates of "extreme" obesity have grown dramatically. Rates of adult Americans with a body mass index (BMI) of 40 or higher have grown in the past 30 years from 1.4% to 6.3% -- a 350% increase. Among children and teens (2-to 19-year-olds), more than 5.1% of males and 4.7% of females are now severely obese.
• Rates vary by education. More than 35% of adults ages 26 and older who did not graduate high school are obese, compared with 21.3% of those who graduated from college or technical college.
• Rates vary by income. More than 31% of adults ages 18 and older who earn less than $25,000 per year were obese, compared with 25.4% of those who earn at least $50,000 per year.

In addition to the latest data showing a stable rate for adult obesity, a new report released by the Centers for Disease Control and Prevention (CDC) earlier this month shows 18 states and one U.S. territory experienced a decline in obesity rates among preschool children from low-income families. The report provides state-specific trends in obesity rates among children ages 2 to 4 who are enrolled in federal health and nutrition programs, such as the Special Nutrition Program for Women, Infants, and Children (WIC).

"After decades of unrelenting bad news, we're finally seeing signs of progress. In addition to today's news about the steady rates for adults, we've seen childhood obesity rates declining in cities and states that were among the first to adopt a comprehensive approach to obesity prevention," said Risa Lavizzo-Mourey, MD, RWJF president and CEO. "But no one should believe the nation's work is done. We've learned a lot in the last decade about how to prevent obesity. Now it's time to take that knowledge to scale."