Any way you slice it … There's a reason why pizza boxes don't come with a recommended serving size. It's because some people can finish off one slice and others can probably finish the whole pie. But a recent survey by Amazon Fresh found that the average American is able to eat five slices of pizza in one sitting. That, of course, depends on the size of the slices. But the survey also further confirmed America's love for pizza, finding that the average person eats about 180 slices of pizza each year, and surprisingly, most people prefer frozen pizza over freshly made pizza from a restaurant. But perhaps the finding that pizza aficionados might find most unusual is that many people use a fork and knife to eat pizza, especially in certain states including Connecticut, Florida, Massachusetts, Missouri, Ohio, and Utah.