I tried to read Good Calories Bad Calories by Gary Taubes. I checked it out of the library - twice! The second time I had it for 6 months. No lie. I'm just really not much of a reader.
Taubes explains two major things in his book - why fats have been vilified even though they're not bad for us, and why carbohydrates have been glorified even though they're not good for us. And he does it in magnificent detail with lots and lots of sources. He's an excellent science writer. (This is why I feel so guilty for not reading more of it.)
If you're interested in the material but don't want to march through so many hundreds of pages, there are now two new options for you!
1. Why We Get Fat: And What to Do About It
Gary Taubes has written another book - a shorter, easier book. I've heard it described as Good Calories Bad Calories for the layman, or a watered-down version. It's lighter on the science, and lighter in mass -- it's only 272 pages.
2. HigherThought.net's Complete Notes to Good Calories, Bad Calories
A blogger has written up a concise outline of all the information in the book, which seems to be very thorough! The one disadvantage is the lack of citations, but if you wanted more information about any of the topics, you could go back to GCBC and find the relevant citations pretty easily since the notes are organized by chapter. Supposedly this won't be posted forever, so go there and download the PDF or e-reader version if you think you'll ever want to read it. (And if it's already been taken down by the time you're reading this, feel free to leave a comment and ask me for the PDF.)