Julie, hi again. I was trying to find out about the Royal Canin Satiety food you are feeding Smokey and I can't find that on our food chart:
https://catinfo.org/docs/CatFoodProteinFatCarbPhosphorusChart.pdf
So, I can't say if that is high or low carb food. Many of us start out with Fancy Feast or Friskies pates because it's accessible at the grocery store, and costs less than food you get at the vet. We don't recommend feeding any dry.
I learned that an unregulated diabetic cat can't properly utilize food and that it's better to offer more frequent small meals to help with the hunger issues.
Did the vet talk to you about testing Smokey's blood sugar at home? We use this testing to know what the blood glucose level is real time; as opposed to visits to the vet which can cause higher test readings due to stress, and is intermittent at best. Do you remember what the BG was at diagnosis, and did the vet do one blood sugar reading or was there a Fructosamine test done? A Fructosamine test is like an A1C test for humans, a BG average over a period of time.
We can help you learn what testing supplies you will need and how to home test. Even if you are not using insulin yet, it's a good idea to see how the BG (blood glucose) is affected by a low carb wet diet. Testing is essential if you are injecting insulin. We always test before an injection to make sure it's safe to "shoot", and then during the 12 hour cycle between shots, to determine the lowest BG in that cycle. If you are making a diet change while using insulin, it is especially critical, as a low carb diet can significantly reduce the BG, and you need that information to intervene and prevent a hypo.