Nutro Max diets have more fillers & the such than Nutro Natural Choice. If you were to feed Max she would still need to eat a lot of it. With the NC you don't need to feed as much as the food has less fillers, her body will use more of the nutrients in it.

In the long run a decent food that costs a little more is actually cheaper.
I am trying to find a post or a site with some onfo on why feeding a decent food is actually cheaper in the run. I know I have seen them before and I already know the reasons why but I thought it would be a great article for you to show your mom.

Give me a few moments while I look for it.