"Throw him in the dungeon! Give him only bread and water!" - any medieval or fantasy tyrant worth their salt.
"It is not the bread and water I fear. I can live on bread - when have I asked for more?" Joan of Arc (per George Bernard Shaw)
"I. Love. Bread." Oprah
Hm... One of these things is not like the others.
Ah, bread. The staple of civilization. The most basic of basic commodities in Western and Middle Eastern culture for millennia. Cultures are defined by the bread characteristic to them. Open a story with the description of a meal - whether the bread on the table is a baguette or biscuits - and you've solidly placed a setting in the reader's mind. And what else? Is bread the ONLY thing on the table? Is it stale? Is it white or coarse wheat? Is it merely there along with a mountain of meats and delicately prepared exotic fruits and vegetables? Each of these scenarios says a lot about your world and your characters.
And yet now... now, there's a movement - dare I say an obsession? - with eliminating bread (or, more specifically, refined carbohydrates) from the diet. What was the most basic staple, the food that even the most hated prisoner was allowed, has become a special treat: "I've been good on my diet all week - I'm going to have a roll with dinner." I wonder, 100 years from now, if someone reads a story (a "chick lit," a YA that deals with dieting and body image issues, etc.) if that person will be confused as to why the character in the book eschews bread... or confused as to why bread is even an option. (No, I don't really think the latter is going to happen. 10,000 years of the existence of bread isn't going to be toppled by a couple decades of a diet fad. We'll have a new obsession in 100 years.)
So, bread - the basic food. ONLY bread - the "punishment" food, or the "reward" food depending on what era you're talking about. A friend and I were talking about another "punishment" food the other day.
"Why do we eat bitter herbs and unleavened bread, my uncle?" Eliezar, The Ten Commandments
My friend is Jewish, and shortly after Passover, her husband found huge box of matzoh at Costco - a four or six box package for a dollar, or something ridiculously cheap like that. "I know it's supposed to be the 'punishment' food." She shrugged. "But I like it." Funny thing is, I like it, too (and I'm not even Jewish - we always just had it around when I was a kid). She gave me a box. Later that afternoon, I sent her a picture of the "punishment" food all dolled up with peanut butter and sliced pears. Yum!
And the bitter herb thing? My sister used to eat parsley straight. And the flat seaweed sheets you're supposed to use for sushi. We both like matzoh. I like kale. I once scared all the kids in my first grade class because I told them my favorite food was spinach. For most people, the thought that you HAVE to eat these stronger, often bitter, greens for your health is less than desirable. But for me? Sure, I'll take that kale salad. Can I have a side of matzoh?
But, then again, I also love bread.