Food definitely affects the BG's.
The thing here is to stick with the dose you are on, UNTIL some of the more experienced dosing folks tell you to change. They will follow the protocol you read about above and help guide you through this.
As was discussed yesterday, if you change the food to something lower carb - say 10% or lower on the food charts, you should start to see if affecting the BG's.
To give you some examples of low carb options, I'll tell you what I've fed and currently feed my girls:
Fancy Feast - now called the classic options
turkey & giblets feast
beef feast
beef & liver feast
chicken feast
Friskies
Special Diet - turkey & giblets
EVO 95% canned
tried them all, my girls like the chicken/turkey - whichever flavors you try, make sure the label says 95% on it.
Nature's Logic canned - all three flavors
Raw
Nature's Variety
Feline's Pride - mail order only
homemade