Even though you're supposed to be "healed" i'd go easy on food. When i had a resection for the first 2 months i didn't eat much. Was mostly living on chicken soup and avoided too much meat.
I started gaining weight only 6-7 months later althought i had started eating normally after 3-4 months.
So don't rush into it. You won't even have to make an effort, you'll just start gaining it without stuffing yourself.