I was always smaller in size than a lot of people growing up. You can drink all the weight gain powder you want...but if you don't eat correctly with high-intensity weight training...it won't do shit. First off..cut out fast food from your diet. Also...tobacco/nicotine and caffiene increase your metobolism, so cut down or cut those out as well.

How to gain weight and gain muscle mass

Go to that site...it's got some really good info to read. I actually got the ebook a few years ago...and it is extremely helpful (I dunno if it's free...it was like $10 then). SO worth it though. There are three or four types of body structures. What you are considered is a hard-gainer. Basically what will work for someone that gains weight easily...will not necessarily work for you or the other body structures. That's why this e-book is good...it's focused solely on the hard-gainer type and goes step-by-step on how to keep track of calories, carbs, and protein...gives weight training tips/steps. Also..supplements are a big part. You can't relie on them by themself..but added with the eating, shakes, and lifting...they can help immensly.

I love how there are 1000000's of ways to lose weight, but when it comes to gaining...it's suppose to be a 'given' just to eat more. Eating less will not necessarily lose weight and eating more will not necessarily gain...that can work...but everyone is different and sometimes it takes a combination or something totally different to either gain or lose.