we as dieters can say this, look, i like diet soda. i'm going to keep drinking it and see how i do if i keep dieting and exercising. empower yourself to be your own study subject. you don't have to listen to the beverage industry. do it yourself and see what works best for you. >> i have my vices, but i tell you, i went cold turkey on any kind of soda some time ago. i felt it kind of made me nuts. elizabeth cohen, thank you so much for that. this is something really exciting here at cnn. coming up this thursday, 9:00 p.m. eastern and pacific, make sure you tune in to the ten-part series called the sixties. it's a look at pop culture that changed the world. each episode is executive produced by tom hanks and gary guessman. here's a preview. >> our government is asking us as citizens to refrain from traveling to foreign lands. >> okay. all you guys in vietnam, come on