One topic you might consider, which could be both interesting and contraversial is the effect that the increasing numbers of morbidly obese patients is having on our healthcare system; ie, the amount of dollars they eat up as a result of their obesity - the diseases which they acquire or have and are exacerbated by their obesity - CAD, PVD, NIDDM, COPD - the effects that obesity has on patients who must undergo surgery - here's one link that could get you started, if you wanted to pursue this as a topic
http://www.cdc.gov/nccdphp/dnpa/obes...nsequences.htm