Why would a cat GAIN weight on a diet?

Hi there, here with Robins diet update. He's 15 pounds now. What am I doing wrong? He's getting 1/4 cup dry twice a day, half a can of wet (Sheba or Purina Beyond) once a day (doesn't eat all of it). The heat has him lethargic.

The problem right now is I'm almost worried he's not eating enough. The store was all out of his favorite dry so I bought some in a different formula, which he doesn't like much. He's almost out of his favorite dry, and the store I go to may not get any more for a few days, so I'm a little worried. As a result I'm giving him canned, Sheba or Purina Beyond, but he's not ravenous about anything right now. It's hot and my apartments central air is barely keeping it below 75°.

I'm really frustrated and hoping it's not something else, like thyroid issues, or retained water. He does pee a LOT, always has. He seems okay other than sleeping a lot, which seems normal given the heat.

Why isn't he losing weight...?

The dry food has a lot of carbs which makes them obese.

I can't give you an answer, but you might find this interesting [thread="302031"]​[/thread]. If Robin continues gaining despite his diet I'd suggest you get him checked out and have full bloodwork done - just to be sure there isn't an underlying cause.

Yea, about the dry. Purina One is full of corn products. But as a feral kitten, the only thing I could get him to eat was cooked chicken breast. He did great on it, but sometimes I can barely afford food for myself, much less my cat. Switching to cat food, it took about 5 months to find something he liked. (He loved one of the cheap dry foods but he'd barf like crazy).

He does like the Friskies turkey. It's not expensive, but it's not high quality. However I might wean him off dry and try to get him canned 75%. Robin doesn't do Fat well at all; it doesn't suit him.

Thanks, to both of you.

Switch him to a good grain-free food.  Feed mainly canned, but supplement with dry food.  I give my kitties 1/8 cup or less gry food a day.  Cut out any treats, too.  If you free feed him, switch to scheduled feedings.  He'll act like he's starving, so redirect hum with an interactive toy like a feather on a wand or a laser pointer.