The feeding guide, on the bag, is just that, a guide, a place to start. You have to adjust up or down, depending on your cat. Each cat is different. Some cats have a higher metabolism, some have a higher activity level, and it depends, on what your doing with them.
We already know this, from the horse world, the feeding guide is just a place to start, you adjust up or down.
For horses, there are like a zillion factors. If they are a easy keeper or a hard keeper, if they are a show horse, or just trail riding, if a show horse, are they campaigned heavy, is it a mare, is she bred, is she lactating, is she open, if it is a stallion, is he being used to breed, or is he being shown, or is he just open. We got like a zillion different protein % and fat % combos to choose from, depending on how the horse is being used.
Bump is about as big as a horse, mol, but he only gets 1/8 cup each feeding, and that boy, ain't thin, its what his vet figured, he needed, and she was right on, based on the kcal count. Now, the feeding guide, recommends, for his weight, he should get 1 cup per day. For him, that is way way too much. But, its a good quality grain free food, that is higher in protein and fat, because he is a show cat. One kitten gets more, than the recommended amount, he has a higher metabolism, the other kitten gets less than the recommended amount, brothers from the same litter, both show cats, they each get a different amount.