Hello!!
Some GREAT puppy foods & all life stages food include:
-Innova Puppy (they also make EVO which is all life stages, grainfree, and high protein kibble-my pup did not gain weight from it, we still feed it)
The Healthiest Pet Foods in the World – Natural & Organic Pet Food – Natura Pet Products
-Wellness Just for Puppy (Wellness does not carry an all life stages food)
-Merrick Puppy Plate (an all life stages food-all Merrick is)
-Taste of the Wild (grainfree-higher protein-all life stages)
-Instinct (same company who makes Prairie-grainfree-all life stages)
I think your idea of going to an all life stages food is good b/c your 5 yr old will most likely not loose the weight eating puppy food since puppy food is higher in fat. Actually taking the Ceaser food away will def help in loosing the weight, that food is like feeding fast food to your dog. Very tasty but not healthy. And I think Prairie is an all life stages food isn't it??
Good Luck to you!!
Snick & Viv