An obvious conclusion to draw (or jump to) might be be to simply feed cats an all-meat diet. Catch 22: nothing is ever simple. Certain amino acids in meat have upper limits on their allowable concentrations which if exceeded can have a negative impact on the metabolism. This is especially true for aging cats and some clinical conditions which are exacerbated by particular amino acids or even by any significant excess of protein above required levels.
The "ideal" diet, therefore, is one designed to meet the requirements for all essential nutrients while avoiding excesses of any that could cause an imbalance or negative influence.
Fortunately these requirements have been well studied and quantified, so scientific recipe design can be broken down into relatively simple calculations. A complication is that the actual requirements are a moving target. Not only are they expressed as a percentage of weight, they also have to be viewed relative to concentration of calories. This means that if the energy density in a recipe is changed by increasing its fat content everything has to be recalculated. There are also inter-dependencies between specific nutrients. On average 100-200 calculations must be made for even very slight changes in a recipe, making the use of computer software essential.
Equally important to the design of a recipe is its appeal to a particular cat. Traditional commercial cat foods are limited in variety and constrained by the need to use bulk ingredients with preservatives to ensure a suitable shelf life. There's a surge in the marketplace of new companies marketing "boutique" cat foods with ingredients varying from bison to blueberries and while they're different they still represent what their designers "believe" is good for cats but with no guarantee that everyone will like them. (I've never had a cat try to steal broccoli off of my plate!)
Due to a desire of many pet "owners" to feed their cats the freshest and highest quality ingredients available many are seeking to give their kitties home-made meals. Nobody knows better than we do what our cats really like, the challenge is to make sure that what we give is at least as nutritionally sound as commercial foods are expected to be.
The purpose of this website is to provide tools to design recipes from practically any ingredients in combinations that will satisfy both the palates and the nutritional needs of cats in any stage of life.