Being a writer gives one a unique perspective on topics as mundane as quick trim celluslim reviews to as exotic as the effects of poisons on the human body. With suspense/mystery writers, all of it usually adds up to figuring out how to effectively kill someone in a way that will mislead the reader to the wrong suspects, right up until the moment the real killer is revealed and suddenly it all makes sense.
The difference, really, is that you get fewer strange, suspicious looks when asking about diet plans than when one asks about poisons. Which, I guess, makes sense.