Most of the time when I embark on such an investigation, it quickly becomes clear that matters are much more complicated and ambiguous—several shades grayer—than I thought going in. Not this time. The deeper I delved into the confused and confusing thicket of nutritional science, sorting through the long-running fats versus carbs wars, the fibre skirmishes and the raging dietary supplement debates, the simpler the picture gradually became. I learned that in fact science knows a lot less about nutrition than you would expect—that in fact nutrition science is, to put it charitably, a very young science. It’s still trying to figure out exactly what happens in your body when you sip a soda, or what is going on deep in the soul of a carrot to make it so good for you, or why in the world you have so many neurons—brain cells in your stomach, of all places. It’s a fascinating subject, and someday the field may produce definitive answers to the nutritional questions that concern us, but—as nutritionists themselves will tell you—they’re not there yet. Not even close. Nutrition science, which after all only got started less than two hundred years ago, is today approximately where surgery was in the year 1650—very promising, and very interesting to watch, but are you ready to let them operate on you? I think I’ll wait awhile.