Why We Get Fat and What to do About It by Gary Taubes (nonfiction)

A truly readable version of Good Calories, Bad Calories, this book takes down the "calories in/calories out" myth scientifically.  It also follows the extensive history of the low-carb diet, and explains how and why we've veered away from what works.

I think the book needs an update/caveat.  The crux of Taubes' argument is that insulin response controls fat storage, but he goes on to say that artificial sweeteners are OK if a dieter needs something sweet.  Recently it has been shown that artificial sweeteners precipitate an insulin response.