When did "fat" become a four-letter word?  Leaders of the body acceptance movement say we've become a fat-phobic nation, and it's time to stop shaming fat people.  In this hour, curvy girls and plus-size women talk about the emotional and physical costs of America's toxic obsession with weight and body image.  Brittany Gibbons on Fat Shaming; The Science and Politics of Weight Obsession; A Reading from Dietland; Sarai Walker on Dietland; The History of the Gym; Ruth Reichl on Food Culture.