Last year, PepsiCo started printing real potatoes onto every bag of Lay’s. The reason? In a world where people are increasingly concerned about the provenance of their food, 42% of the population didn’t realize that the world’s most popular potato chip was made from potatoes. So they put a potato on the packaging. And now, the company is updating Tostitos bags—the most popular plain tortilla chip in the world—with a similar strategy. While Lay’s got a dose of potatoes, naturally, all To...