Lots of good info here, it is the Purdue study
Epidemiology
I couldn't find it but I thought I had read about the citric acid there too. If the food contains citric acid and you add water that is supposed to be a contributing factor in bloat. Innova doesn't have citric acid but Solid Gold does. Also chicken fat being the fourth ingredient or less is a risk factor. If there is chicken fat there, I like to see it far down the list, makes me feel better.