McDonald's, Pizza Hut, Burger King and KFC have costs that never appear on the menu. Chew on This by Eric Schlosser is a hard-hitting revised version of the best-seller Fast Food Nation, adapted for teenage readers. The author shows how a pound;300 million budget is spent on persuading children to eat and drink things more likely to make them fat than fit. We learn about the chemicals that go into milk shakes, about the nasty secrets of slaughterhouses - and about healthy alternatives to all this dubious convenience. The book is published by Puffin at pound;5.99.