Greetings fitnessGAF!
At the start of my third year of college, I weighed 125 lbs (I'm 5'9"). In about February of that school year, I started a variation of rippetoe's starting strength routine. By May, I was 150 lbs and had increased my lifts significantly. Unfortunately, a few months later I was unknowingly onset with celiac's disease. No matter what I did, I couldn't gain weight and I had trouble eating a lot of food. Fast forward to May of last year and I finally got my positive celiac's diagnosis. The state of my intestines wasn't great and having to go on a strict gluten free diet messed me up fairly badly. I dropped back down to 125 lbs. (You can search this thread, I actually asked back in Aug last year if anyone knew anything about good gluten free diets).
I've since tried to return to the gym in bouts (usually one month at a time), but was unable to commit properly due to continued pains and such. Well, I finally went back to the gym two weeks ago and I'm happy to report that I'm gaining weight again! I can't express how good this feels. In two weeks I've gained 10 lbs back Not much but I hope I can get back to 150 lbs and my old lift numbers in a few months!
Just thought I would come post this here since it feels good finally.
Congratulations brother! With GF bring such a big part of society these days, research should definitely help you find ways of keeping the weight on!