>>elisabeth: welcome back. time for quick headlines. o.j. simpson busted again, this time for stealing cookies from the prison cafeteria. he was caught hiding more than a dozen oatmeal cookies under his clothes. simpson may want to lay off the dessert. he reportedly weighs about 300 pounds do you live in one of the most honest cities in the world. reader's digest dropped 100 wallets to see who would return them. right here in new york city, the least honest, less than portugal. to an honest guy, steve, what do you think about that? if you had my wallet, would you give it back? >>steve: not keeping cash. don't worry. a startling study says drinking too much caffeine could slow down brain development in teenagers. that's alarming considering caffeine use in teenagers is up 70%. let's talk to dr. marc siegel from the medical a