Patti Neighmond's "What is making us fat: Is it too much food or moving to little?"

This NPR story by Patti Neighmond is about determining the underlying cause of U.S. obesity epidemic. As the name of the segment states, it seems to come down to food consumption and exercise, but which is the culprit? This is a good example for research methods because it describes methodology for examining both sides of this question. The methodology used also provides good examples of archival data usage.