Six months ago, one of us stood in a supermarket aisle holding two pouches of cat food. Same price. Same cheerful packaging. Wildly different ingredient lists. That moment is why this journal exists.
Cats are obligate carnivores.1 That is not a lifestyle choice — it is biology. Their bodies are built to extract protein and fat from animal tissue. They have no meaningful nutritional use for grains, corn starch, or sugar. And yet, walk into almost any supermarket in the UK, and those are the ingredients quietly propping up the majority of cat food on the shelf.
What fillers actually are
Fillers are ingredients that bulk out a product without providing meaningful nutritional value. Grains — corn, wheat, rice — are the most common. They are cheap, they bind dry food into kibble shapes, and they make the protein percentage look higher on paper. They also spike insulin, contribute to weight gain, and offer very little to a cat's gut.4
Sodium is another one to watch. Added salt improves palatability but does nothing good for long-term kidney health. Meat and animal derivatives is the phrase that deserves the most suspicion — it means any part of any animal, with no specification on quality or origin.
What good looks like
A food we feel comfortable recommending lists a named protein first — chicken, salmon, turkey, duck. It is high protein (above 8% in wet food, above 30% in dry). It is grain-free. It carries no added sodium. And ideally, it is compliant with FEDIAF guidelines, the European standard for pet food nutrition.5
Wet food, in most cases, is the better base. The moisture content alone — typically 70–80% — supports kidney health in a way dry kibble simply cannot.6 Most cats do not drink enough water on their own. Their wild ancestors absorbed the majority of their hydration through prey.