Super Size Me (2004)
Director: Morgan Spurlock
By now, everyone's familiar with Morgan Spurlock's 30-day run of eating nothing but McDonald's. That's the premise in a nutshell. Spurlock eats, you watch. He visits the doctor to see how his eating is working out for his body, you wacth. Spurlock eats some more, you watch.
The results—fast food is not good for you—won't surprise anyone but the doc is interesting for its insight into the power of the image. You can read about calories and processed foods all you want, but there's something about seeing these things that affects you on a visceral level no nutrition facts print-out can.