I honestly have not heard of that, but my own experience is that all vets I have talked to typically will push the prescription food angle. I chose to research food on my own and we have regulated Moby well on that research. He is also a "pate' guy" and enjoyed the Fancy Feast turkey n' giblets, Wellness Core, and Halo's grain free Spot's Stew. We also gave the Young Again Zero Carb a try for mid-day snacks and he really enjoyed that.
It's a hard decision to make, I know! I had to find a balance on who's expertise I would take and who's I would discard, and I wish there was an easy answer, but that's something only we can do for ourselves and our kitties.