I still remember my flight back to America after four months in Tokyo. It was a United flight, and it followed four months of eating a predominantly Asian diet. United, of course, served "American" food on the way back to the States (as a matter of pride, I suppose), and the dinner was accompanied by a rather large block of chocolate cake. After having a few bites of whatever entree they had that evening (I remember some meat-like product covered with a rather thick gravy that obscured the blandness of the overcooked vegetables, but was undercut by a saltiness that can only be equated with taking a sip of Dead Sea water), I gave up and took a bite of the cake. It was so overwhelmingly saccharine that I could only muster a bite or two, at which point I resigned to hunger for the duration of the flight. Yet I was intrigued - the cake was no longer even a food item, but instead a vehicle for ingesting massive amounts of high-fructose corn syrup and other sugars. How had I not no...