New state-by-state rankings of obesity rates have been published today by the Trust for America's Health and the Robert Wood Johnson Foundation. Tennessee ranked as the fourth-most obese state in the country behind Mississippi, Alabama and West Virginia.

And while the nation has long been bracing for a surge in Medicare as the boomers start turning 65, the new report makes clear that fat, not just age, will fuel much of those bills. In every state, the rate of obesity is higher among 55- to 64-year-olds – the oldest boomers – than among today's 65-and-beyond.

As in previous years, Colorado is the only state with an obesity rate below 20 percent.

SEE ALSO: Our recent print-edition story on how human behavior will factor into health care reform efforts.