[ekianjo]

I know. That's why I mentioned clearly "especially for a medical condition" - because then you use a figurative word associated with a medical term, while you would expect in that context the other meaning of "epidemic". If you were talking about "epidemic unemployment" there would be no ambiguity, but "epidemic obesity" is a very improper use of the word, ambiguous in this context.

Anyway, most of the time if you use the figurative sense of the word, just replacing it with "growth/increase/spread" is good enough. Why use an overly dramatic word ?

[andrewfelix]

But it's not incorrect or even unusual in a medical context. Epidemic has often been used for non contagious conditions including diabetes, ADHD and obesity. It's a dramatic word, but the obesity rate in the US is dramatic.