What is the difference between a premium food and all the others?

Quite simply, quality. Premium foods as opposed to cheaper foods have better quality ingredients, meat not meat derivatives, rice or corn, not soya, animal fats not vegetable fats. The ingredients used are predominantly animal in origin - as we know meat is always more expensive than vegetables or cereals, just look at your weekly shopping bill! Cheaper non-premium foods' first ingredient will usually be a cereal of some sort and the 'meat and animal derivatives' may feature well down the list of ingredients. By law, the ordering of ingredients on any packaging must list the highest percentage ingredient first - in other words, if cereal is listed as the first, the food has a higher percentage of cereal than any other ingredient! The second ingredient will be the second largest percentage quantity and so on, so if you see meat and animal derivatives third or fourth on the list the food contains poor quality meat and not a lot of it!