Oh, diet culture, how you’ve brainwashed us with your insidious, nagging messages. They were unpalatable even when they were delivered with a wink. In the 1970s, Diet Pepsi chose to suggest a link between its one-calorie soda with concerns about overpopulation, the embrace of the birth control pill, and our country’s expanding girth. Check out that detail on the logo: A neatly closed zipper, showing no strain whatsoever. Drink up!—Linda Wells