Pizza has been a staple of the American diet since the late 19th century and has grown into a multibillion-dollar industry. The Science Behind Pizza’s Feel-Good PowerBest Pizza Chains Photo by Jon Tyson on Unsplash loading...Americans buy approximately 350 slices of pizza every second. As for what's on the pizza whose smell is bringing you good vibes, that, of course, depends. Interestingly, though pizza trends have evolved over time, some things have stayed the same. For example, pepperoni, sausage, mushroom, and extra cheese are the most popular toppings across the United States, according to Pizza Today's 2025 Pizza Industry Trends Report.