What food is givin to prisoners in jail?

I'm writing a novel and one of my characters is in jail. What kind of food do peole get fed in prison?

It varies a lot, but for the most part it's just generic mass-produced cafeteria food. There's an article with more details on it here. It also includes some more information on prison life in general which may give your story more depth too

Edit: here'sanother article about a particular kind of (apparently disgusting) prison food given to misbehaving prisoners as punishment. Thought it might be of some use to know.

Thanks for your help I appreciate it!