Lifestyle tips

I was in a similar situation, not too long ago I was underweight at 125 pounds and had a super fast metabolism, and now I'm overweight at 190 pounds. For me, if I wanted to go back I could, over the summer alone I lost 25 pounds without even trying to lose weight, I just was just eating less, and I gained it all back pretty quickly when I started eating more. A 30 pound weight gain would likely not pose any health problems, not until you start gaining a lot more. I say go for it! I've gained over 60 pounds and haven't regretted it at all, in fact I'm still wanting to gain at least another 40 pounds.

I've heard that one way to go about it is to focus your diet changes on fat based foods and not sugar/carb based ones. Most on here rave about heavy cream, cheeses, and dairy in general if your digestive system can take it. (someone correct me if I'm off)