Last year our long-haired ragdoll kitty had surgery for two impacted
hairballs.  Afterwards, she went from 10 down to 5 1/2 pounds.  I have
wondered if maybe when the vet sewed her back up that her stomach was
made smaller (sort of like a kitty gastroplasty).  

Anyway, she began throwing up food and hairballs regularly.  Whenever
we changed her food type, she would throw it up for a couple of days.
We thought she was just eating too much food and then throwing it up.
This would also happen if we added a little bit of extra flavoring to
her food - like gravy, tuna juice, etc.  She would scarf it down then
throw it back up again.  

She also threw up plant material from snacking on the indoor plants.

Anyway, I wanted to write about how we helped her gain weight and stop
throwing up.  I know that this probably won't work for a lot of people
but I was hoping that it might help some kitty out there.

Anyway, we had noticed that she like to chew on cardboard and paper so
we left cardboard boxes around the house for her.  She does not seem
to swallow the cardboard and it does keep her from chewing on any
plants she can reach.  

And, the most important change we made was to feed her Innova EVO Cat
& Kitten.  We had tried other supposedly high quality foods but she
never gained any weight and still threw up.  Anyway, she is now up to
a little over 7 pounds and she never throws up anymore -- even
hairballs.  

No, I am not associated with Innova in any way and I do know that it
is very expensive, but it is the only thing that helped our cat gain
some weight.  Before giving her the Innova we had been so worried that
she would not live that long as she did not have much energy and there
did not seem to be any fat on her ribs (though she did not look that
bad because of all the hair).  

We do free-feed, so our other cat did gain a little over a pound, too,
but now that our formerly sick kitty has more energy, they chase each
other around and seemingly keep each other more active and healthy.