Let me educate you, since this a topic I know bit about: They're method isn't based on any health dept. stats. or clinical public health research. They check the amount of usage out of certain public recreation areas, which Miami ranks in the bottom. There's a gym in every corner and it's way too fucking hot to run in the park. They couple that in with the amount of TV viewership, which ranks among the topthe the U.S. Then they get the average restaurant per square mile and factor that in.
They also use statistics from the city of Miami, which only has about 200,000 residents and does not include Miami Beach, Coral Gabels, West Miami, South Miami, Pinecrest, North Miami, North Miami Beach, etc.
The reason Miami is a preferred destination of pharmaceutical companies is due to the relative low population of overweight citizens and a general population with relative healthy cholesterol levels. The medical industry is something I know a bit about.
Forgive the typos, I'm on an iPhone.