[mountainhound]

Totw is one of the lowest calorie grain free foods on the market, I would try something like Canidae Pure. For example Totw High prarie is 370 cal per cup vs Canidae Land (bison) is 474, Sea (fish based)-496 and Sky (duck/turkey)- 520.

so you could start out with land for easier transition and go from there. You can also add some digestive enzymes for increased absorption.