Just to add about the psyllium. We aren't to take it with the glass of water as the directions say. The best way I found was to mix a dose in with a little bit of applesauce.
After my surgery the surgeon scheduled out the use of both Imodium and Metamucil (psyllium.)
I'd spread out the Imodium doses to 3 times a day. I think you can also take up to 7 per day. More than 7 won't kill you but it won't provide you with more benefits.
I know it's difficult to maintain weight after the surgeries. There are a lot of good suggestions above. I like the egg one. (I'd eat ice cream but your j-pouch might not like the sugar and I don't recall it causing problems for me.) I also was told to eat marshmallows and they are likely pure sugar.