Healthy ways to gain weight for a teenage girl?

haha i think a health way is to eat healthy foods, but in a way that your increasing your food intake. you can also do some small exercises, but not too much otherwise you will lose. you can also put some muscle on you if you want. muscled adds to overall weight and it can make you look physicaly fit. but dont get too bulky.. i dont think muscly girls a very atractive... but a little muscle is a ok.