Need to gain weight/posture correction

[Halosniper101]

Hey Guys, I am a 17 year old guy who has a problem (: I am living in Kenya while we are adopting... i got Meningitis and i lost 16 pounds. I have a really high metabolism and i have a real problem gaining weight. I am 6ft. and only weigh 120....yeah.... so i kinda need to gain some weight. What should diet consist of to help me gain weight, should it be carbs or protein or what should i do. Since we are in Kenya....the gyms are not the best....they are nothing like back home in Indiana. I am starting to go to one but....i am a beginner and need some ideas on what type of work out i need to do. Also is there any type of workout that i can do to improve posture. Thanks a million guys!!
Alex

[swanso5]

what's wrong weith your posture?

if your that light than basically just eat anything...carbs and protein need to be high on the agneda as well as healthy fats where avocados are very handy in that regard