It's all about survival of the fittest. Looks like you are becoming more fit.
While discussing dog food with a friend the other day, he said that a vet had recommended a food for his German Shepherd. Apparently it had no fillers (junk) and he only had to feed the dog 2 cups per day. The dog lived into his teens, which is quite good for a large breed. He said the dog never had a flea problem.