I am 18 5'6 and 130 lb. I have been taking protien for a year. I currently bench 205 and i am trying to reach my goal of 225. To reach this goal i think i need to gain weight but protein and amino acids dont do anything, i am always the same weight.
you need to track your calories and eat more than you burn in a day. fitday.com is great for tracking calories, it's helped me a lot. also try making your own homemade weight gain bars like phaledax has posted.
