How to make meatloaf with only one lb of ground beef?

You could try to use filler in the meat. Such as add in cubed bread or rice or plain oatmeal to make up for the meat you don't have. My mom always used cubed bread and you can't taste the difference cause the bread soaks up the flavor from the surrounding meat and spices. We don't put ketchup on top but we do put tomato sauce (one of the small cans)