I recently put Lucy back on all raw (was kibble in morning, raw at night) based on our homeopath vet's advice but a few years back when I switched them to a higher protein low carb kibble she
lost weight
. There was basically no calorie difference between the two kibbles but she obviously was able to process the higher protein kibble more effectively.
I would suggest switching proteins as well as going to a higher protein. Her reactions could easily be from allergies and this might cause her to be hyper sensitive to the same proteins even if it is a grain allergy. This means trying Orijen Fish or Acana Pacifica (made by Orijen). They are both great formulas but you might consider buying the Pacifica to begin as it is 33% protein and if you supplement with regular meat already that might be a better choice. It is probably harder to find though then Orijen (it is here anyway).