The book Salt Sugar Fat: How the Food Giants Hooked Us reveals how companies create foods to addict us - from the food science labs to the marketing campaigns.

Even if you're relatively secure about your health and waistline, it's been impossible to completely miss the buzz around the major diet trends of recent years. But is all this nutrition advice actually making us healthier?

Michael Moss, New York Times reporter, talks about the use of firearms in Newtown, Connecticut, and how resistant the area has been to gun control.

Adam Winkler, Constitutional law professor at UCLA and author of:  Gunfight: The Battle over the Right to Bear Arms in America, explains what we know about the weapons allegedly used by the shooter Adam Lanza, what black rifles are and why they are so popular.