The challenge is always the eating, Dino, whether you have trouble gaining weight or losing weight. It’s a piece of cake to work your ass off in the gym, in my opinion, compared to stuffing yourself to the point of puking 6 times a day (which I need to gain weight) or feeling starved-hungry all day (which some guys need to lose weight). I need to get some damn discipline in my eating habits! I work out plenty.
I know that the grass is always greener on the other side. But I know a lot of women who like men who are thin. This is particularly true in Europe. The “working class” ideal is much more pervasive here than in Europe. Europe is fairly split on this matter: North vs. South England, for example. But many of the highly educated “upper crust” in Europe (I speak mostly about England, since this is the European country I know best) view muscles on a man as indicative of manual labor, and thus a lower class. I’m quite muscular, and this goes over much better here in the U.S. than in Europe. But I also find this kind of thinking here to some extent. Anyhow, the point is simply that the brawny type is not a universal ideal for women.
Having said that, I wouldn’t have thought that you’d need to eat that much food to gain muscle mass. Visit a good nutrition store and have a talk with someone who knows a lot about nutrition and exercise. Or go find a coach or trainer to talk to.
As you get older, you’ll most likely gain more muscle mass. The great advantage you will most likely continue to have is, as Dino says, that you won’t gain weight easily. “When I was your age,” as they say, I was fit and muscular; I’ve always had a stocky frame, but when I was young I was lean as well. When I hit my mid thirties, metabolism change big time! Now I too gain weight just looking at food. All that muscle likes to turn to fat. So it’s an imperative that I exercise regularly, which, because I have to do it, is sometimes a burden.