May 2016 - Many people in bigger towns in ancient Rome lived in just one room and didn't have kitchens in their apartments. They ate most of their meals in fast food restaurants like this one in the picture. You can see that one guy is sitting at a booth, while others are standing. There are a lot of clay cups hanging from the ceiling.
In these restaurants - tabernaria or thermopolia - people often ate pizza, just as you do in fast food restaurants. They ate a kind of white pizza with just cheese and onions on it, and maybe ham or bacon, because the Romans didn't have tomatoes yet.
With your pizza, you could also get wine or beer. There wasn't any drinking age in ancient Rome, but still kids usually drank wine mixed with water so they wouldn't get drunk. People also ordered soup, and porridge, and small plates of pickles, ham, pickled beets and onions and hard-boiled eggs and toast with fish sauce on it - salty things that would make you thirsty so you would order more wine, so the restaurant could make more money.
Eyewitness: Ancient Rome, by Simon James (2004). Easy reading.
Archaeology of the Roman Economy, by Kevin Greene (1991). An expert, but a good writer. Greene, like many archaeologists, comes down on the side of a market economy.
The Roman Empire: Economy, Society and Culture, by Peter Garnsey and Richard Saller (1987). Two experts, but their writing is easy enough for high schoolers. By Finley's students, and basically on Finley's side.
The Ancient Economy, by Moses Finley (1973, updated edition 1999). The book that first started this argument. Basically on the side of "consumer cities" and people farming their own food. The writing is, again, clear and simple.