i have a 12 yr old FAT cat and as she got older i was noticing she was "throwing up" more of her food ... i went into my local whole foods store and they suggested the Wellness Brand for overweight cats ...
Mazzy LOVES it and gobbles her dish everyday and she maintains a nicer weight now
it is sorta pricey as she eats about 1 bag per month, and locally here its about 12.00 a bag, but i figure its the least i can do for my baby :)