Answer: Ok it's easy all you need to do is intake more calories then you lose.Try eating alot, that will put on weight.Also eat fatty/junky foods.But while you eat these foods,try to lift weights and work out so it dosent turn into fat.Proteins are required for building muscles, so having high protein foods like eggs, milk, peanut butter, protein shakes will help you in gaining weight. Starchy foods contain a lot of carbohydrates. You can find more information at http://www.toloseweight.org/gainweight.h...