I don't know how "scientific" it is but we now feed all THREE pets (
Ozzie plus two cats
) home cookin.'
Ozzie has been eating this stuff since puppyhood because he has always had an ultra-sensitive gut. We boil hamburger (ground chuck or ground round), chicken breasts, and pork chops (usually sirloin boneless). All EXCESSIVE fat is cut off before cooking. They do need a bit of fat in the diet but I never leave fat around the edges of anything.
I buy canned green beans (the no salt or sugar variety), cook fresh carrots, broccoli, rice and occasionally vermicelli (the really skinny spaghetti), and low-fat cottage cheese. Also now have a healthy supply of Yo Baby! yogurt (vanilla and banana pack).
Once cooked, each type of meat is ground separately by Cuisinart and put in its own container. At meal time, each gets meat and at least one veggie and at least once a day a tablespoon (or so, Ozzie weighs 13 pounds!) each of cottage cheese and yogurt. We switch out what they have so they aren't eating the same thing meal after meal, but it all has the same core ingredients.
Both cats also have a serving of crunchies laid out at least once each day and also get tuna (mixed with one of the other meats) a couple times a week.
The kitten eats three times a day and Ozzie and my aged cat (15 next month!) both eat twice.
NOTE: Ozzie no longer eats pork at vet's advice. I don't necessarily agree, but I don't have DVM after my name! Otherwise, the vet says all our guys eat well and should be getting enough of everything. (Well yeah -- they eat better than ME!
)
Don't know if that is something that would work for you, but has fared well for us.