Weight gain tips on gluten free diet ?

I’ve had trouble gaining weight my entire life, I know that I have a fast metabolism. However I just found out that gluten intolerance runs in my family and that I may possibly be as well. I want to gain just a little weight because I’m concerned about my long term health. Feel like I have to give a 5 paragraph explanation as to why I would want to do that or I receive looks like I have two heads -