Need food Options to help male cat put on weight.

I have posted here before but it has been a while so here is Pumpkin's background story. 

He is an 8 year old male. At three he had a blockage from struvite crystals. He was put on Purina Urinary tract formula and had been fine until almost a year ago. Last October he started loosing weight. In February I took him to the vet and he had dropped from 12lbs to 9lbs. He was diagnosed with IBD and completely taken off of dry food. A full blood panel was done and thyroid levels were normal. There were no signs of any other illnesses as well. I have had an ultrasound done by the vets specialist and he did see a definite thickening of the intestinal walls. There were no signs of cancer. Pumpkin really hasn't shown any major signs of IBD except for the weight loss. 

Right now he is on Fancy Feast classic varieties, I know not the best but it is what I can afford right now. He has been doing well on it as far as not having any flare ups. He CAN NOT have anything friskies as well Natures Variety Instinct, both have made him sick. He doesn't care much for Soulistic or Weruva. May try a couple of cans of hound and gatos.

I would like to know how many cans he should be getting a day? he usually gets 2 to 2 1/2 cans a day depending on his appetite. Also what can I supplement his diet with to help him put on some weight? I would like to get him up to about 10lbs. 

Someone had mentioned kitten food cause it is hgher in protein and I was curious to know if this was safe to do. Someone has also mentioned chicken livers.

Thanks Jenn

The FF classic pates are actually not bad, high in animal protein, low in carbs. You are feeding the average amount of food as most cats do seem to eat about 5-6 oz of canned food a day. Have you tried feeding him more of his current food since you know he does well on the FF? I hesitate to try new canned foods with IBD kitties since it's hard to know what might set off an IBD flare. I do like Hound & Gatos, but it contains xanthan gum which is corn-based, so if you know he has an issue with corn, that wouldn't be a good choice. I like EVO too since it's high protein and high fat which your boy could use, but it contains carrageenan which may be a concern for IBD kitties.

You could try supplementing with raw (or cooked) meat as well. As long as it's less than 15% of his total diet, you don't have to worry about supplementing or balancing it. If you prepare meat at home, try giving him a few small slices. If you cook it, just cook it plain with no spices and serve with the cooking juices/liquids. No cooked bones though.

Thanks i will keep feeding him the fancy feast. As far as human gradecfood goes he usuallybturns his nose up at it but I will try and see if I can get him to eat some. going to talk to the vet on Monday and see if she has any other recommendations as well.