I'd go to a church shelter or some charity giving away free food
Beans, rice and pasta. Like someone suggested, there are food pantries everywhere. Unless their "pride" gets in the way. If that's the case they aren't starving yet.
Tuna noodle casserole ( from scratch ) or any kind of casserole. You'll have to eat the same thing a couple of times, but you can make huge pot of it for 20 bucks.
Beans, cornbread, fried potatoes, noodles, oats, bread, eggs and Peanut butter. If you have syrup and bisquick you can make pancakes with applesauce even if you are out of milk/eggs. Breakfast for dinner is cheap too.
Cheap canned bicuits fried in veg. oil and rolled in sugar make great deserts too.
You won't lose weight but you will live.
You can make pan gravy with oil and flour and water and salt/pepper, and get out a can of those cheap biscuits or make some with bisquick. I always made big pots of things, like beans or chili or spaghetti sauce, you can use left over sauce sauce for hot dogs too, just add some chili powder.....
If you have bread and eggs you can make French Toast. (or egg sandwiches).
Soup and crackers make nice lite suppers in the winter too.
Lentils and onions for lentil soup. Red beans and rice for chili. Pasta a sauce. Peanut butter, jelly and bread.
I don't know if it's possible, 3 meals a day, 7 days a week. 3 people that comes out to about 16 cents per person per meal. The only thing I can think of in that price range is ramen noodles and going 42 meals in a row eating those, oh boy, I don't know. I really hope there is a food bank or you can get emergency food stamps as this sounds bad.
pasta and sauce, you may have to eat it alot but at least you'll eat. Pasta with oil and garlic. you can do many things with pasta.
I woud make things that would last for several meals like a big pot of beans, a pot of potato soup, a tuna noodle casserole, things like that. I would also fix something like oatmeal for breakfast because it is cheap and filling and it stays with you for a long time.
There are agencies in every city with access to food banks. Food banks in our area do not require proof of income. They will ask you what you need, prepare you a box, and you will pick it up.
Dunno what to say :(
Hopefully this is a rhetorical question, but If you shopped sparingly and bought the essentials you could make it a week. It may not be the healthiest menu possible but you could swing it. I was in a similar situation once with a friend, Canned foods and ramen noodles are the way to go you can buy alot for 20 bucks.
Lots of beans (full of protein) and bread! A chilli can last up to two or three days or a spag boli.. cheap cuts of meat. I think $20 dollars is probably equivilant to about £12.... that's not bad as long - I have lived on two bob and a conker with two kids to feed.... go to the supermarket late at night when they are clearing the shelves you get things 75% off.
Failing that pop over to a friend's/family just as they are serving dinner (I've lived a week like that!)
Pasta is inexpensive and filling. Toast and butter if you have it. Peanut butter is great for protein, but is expensive. Watch for sales and coupons, sometimes you get lucky.
You could go to your local food pantry. There are many communities and churches that offer help to people in situations just like this.
beans and rice bread cans tuna maccoronis,pack cheese,eggs you can come with some meals and if must go to foodbank or church for help...take care we are at times where we have to make due it sucks