Here is a great post on frugal eating from a lady with ten kids!
Her list is similar to past lists from the LDS church. And what she cooks is similar to what I cook, although I have MANY convenience items thrown in there.
Here is another one of her posts that talks about eating when you are living at true poverty level. Although, one of the comments posted points out that many in true poverty have no refrigerator, freezer, or stove.
These posts are great reminders for those who are not poverty-stricken for how to eat frugally, AND very healthily.