My parents dog (Belgian Malinois/German Shephard/probably something else mix) ate Old Roy for years - until we had a family friend at Purina who got us high quality food super cheap - and she lived to be 15, stood 27in at the shoulders, and weighed in at 115 (at her tops) without being fat. Seems like she did ok on sawdust and red paint ... and table scraps. 
