Clean plate ranger

Does anyone know the origin of the phrase, "clean plate ranger"? We used it in my family for as long as I can remember to describe someone who is diligent at the dinner table. I always thought it was peculiar to us, but apparently it has wider usage.

I haven't heard the "ranger" phrase before. The "Clean Plate Club," membership in which children are urged to earn, may be more common. ~rb

I haven't found it in any of my references. Yet. A search online shows that it is in common use. It has to be from some children's program.