Yeah I used to work at a restaurant that had a pretty broad menu. Everything from burgers/steak/ribs to salads and some Asian and Indian inspired dishes. We did have pizza on the menu, 2 sizes, 8 inch small, 10 inch large. 10 inch is NOT a large pizza. But it was meant to be ordered and eaten as a meal by one person.

So if a medium is like 10 or even 12 inches I can totally see a hungry person eating the whole thing.