Below is a great, but scary, interactive map from CNN on the progression of obesity in the US, by state over time. In 1985, more than half the states did not even maintain data to track the overweight problem. Since then, year by year, this interesting map shows just how quickly the obesity epidemic is moving. As recent obesity data has shown, the south and mid-west are leading the charge with the majority of these states (and states in other regions) weighing in with more than 25% of their population obese.
Of course, obesity is determined using BMI, which can be a spurious measure for people who pack on a lot of muscle. Unfortunately, based on study after study, this segment of the population is probably too small to really throw the BMI completely out the window.
Behold, the new red and blue! Click on the map for full interactivity.