James Wellbeloved contains quite a lot of filler carb: White rice (min 26%), lamb meat meal (min 26%), maize gluten, lamb gravy, potato protein (min 2.5%) to name the first few ingredients.
While perhaps slightly more expensive, Orijen - contains 75% meat, 25% fruit and vegetables (and 0% grain). And real meat is the first ingredient, followed by meat meal: Orijen Cat | Orijen Pet Foods .co.uk
Applaws do an 80% meat dried food which is very good but you still need to make sure that your cat drinks plenty of water.
Even if you don't want to feed raw, wet food is still so much better than biscuits