Watch out where you relocate. Certain cities are just blowing up, and if you end up there, you might end up blowing up too. About a third of all Americans are now considered obese -- and that's not 5 or 10 pounds overweight. Obesity is a serious health risk. So which cities are the fattest? Read on...

Memphis, TN - home of Southern fried food, and an obesity rate of 34%.

Birmingham, AL - With an over 31% obesity rate, Birmingham residents may have been indulging in too much barbeque.

San Antonio, TX - Remember the Alamo? No? Remember the Tex-Mex food? Yeah, Tex-Mex, yummy though it may be, is probably responsible for this city's plethora of obese citizens.

Riverside/San Bernadino, CA - I'll bet you thought everyone in California was slim, tanned and wearing a bikini - right? Wrong. This area, an hour east of LA, boasts an obesity rate of over 30%.

Detroit, MI - Sadly, people who live in poor neighborhoods often suffer from poor diets. Thirty-three percent of Detroit residents live below the poverty line, and almost as many ((30.4%) are obese.

Jacksonville, FL - Perhaps it's a combination of heat, humidity and lethergy, but Jacksonville is in the top 10 of obese cities.

Nashville, TN - Have you noticed that many of these cities are in the south? Unfortunately, southern cooking (though delicious) is often extremely fattening as it is frequently fried or cooked with lard.

Oklahoma City, OK - The good news is that these cities are starting to recognize that there is a problem and are trying to do something to fight it. The Oklahoma City Mayor has been a driving force trying to promote healthy eating.

Kansas City, MO - Yes, another barbeque town. It's hard to stay fit and trim when faced with pulled pork sandwiches and ribs.

San Diego, CA - Now I'll admit, this one surprised me. Not just because it's in California, but also because you would figure that in a place where the weather was so beautiful, people would be out exercising, or at least walking. Experts attribute SD's almost 27% obesity rate to poorer areas with larger hispanic populations who tend to eat a less healthy diet.

Do you want YOUR city to show up on this list next year? I don't. So get out there and play your part. Eat healthy (or healthier) and get some exercise. Keep your BMI below the obesity level!