When my mother was trying to feed a family of seven on mere pennies a week, it was common for her to grind carrots and/or potatoes and put them in meatloaf. One carrot and/or one potato would extend that meatloaf and we never left the table hungry.
Sometimes, if she didn't have those handy (just before payday) she would add rice to the meatloaf. Most of the time, we never knew that it was for economical reasons. We just knew it tasted good and we left the table full.
For those of us that played in the foothills or our friend's orchard all day, filling our stomachs was vastly important!