Check out this survey that compares popular food choices, via the supermarket, then (1980) and now (2010).
Number 10 on the list is soda pop, with 51 percent reporting that they purchase it regularly. This is compared to 74 percent who put soda pop in their shopping carts on a regular basis in 1980. Even with this decline some experts estimate that Americans drink nearly 600 cans of soda pop a year.